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 notch groove. The pressure relief body comprises a pressure relief part, the pressure relief part is configured to be opened when the internal pressure or temperature of the battery monomer reaches a threshold value, so as to release the pressure in the battery monomer, the pressure relief part forms a first opening side on one side in a first direction, the pressure relief part forms a second opening side and a third opening side on two sides in a second direction, and the first direction is perpendicular to the second direction. The notch groove is arranged on the pressure relief body, the notch groove defines the pressure relief part, the notch groove comprises a first arc-shaped groove and a second arc-shaped groove, the first arc-shaped groove extends from the first opening side to the second opening side, and the second arc-shaped groove extends from the first opening side to the third opening side. The arc-shaped design of the first arc-shaped groove and the second arc-shaped groove can prevent the pressure relief part from being unable to be opened in a large area, and the safety of the battery monomer is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a pressure relief device, a battery cell, a battery, and an electrical device. Background Technology

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery technology, in addition to improving the performance of individual battery cells, safety is also an issue that needs to be considered.

[0004] Therefore, improving the safety of individual battery cells is an urgent problem to be solved in battery technology. Summary of the Invention

[0005] This application provides a pressure relief device, a battery cell, a battery, and an electrical device, which can effectively improve the safety of the battery cell.

[0006] In a first aspect, embodiments of this application provide a pressure relief device for a battery cell, comprising: a pressure relief body including a pressure relief portion, the pressure relief portion being configured to open when the internal pressure or temperature of the battery cell reaches a threshold, thereby releasing the internal pressure of the battery cell; the pressure relief portion forming a first opening side on one side in a first direction, and forming a second opening side and a third opening side on both sides in a second direction, the first direction being perpendicular to the second direction; and a scoring groove disposed on the pressure relief body, the scoring groove defining the pressure relief portion, the scoring groove including a first arcuate groove and a second arcuate groove, the first arcuate groove extending from the first opening side to the second opening side, and the second arcuate groove extending from the first opening side to the third opening side.

[0007] In the above technical solution, the grooves on the pressure relief body define the pressure relief section. When the internal pressure or temperature of the battery cell reaches a threshold, the pressure relief section will open along the grooves. Because the first arc-shaped groove extends from the first opening side to the second opening side, and the second arc-shaped groove extends from the first opening side to the third opening side, the arc-shaped design of the first and second arc-shaped grooves allows the pressure relief section to smoothly open from the first opening side along the first and second arc-shaped grooves to the second and third opening sides, respectively. This results in a large pressure relief area, reducing the likelihood of the pressure relief section failing to open significantly and improving the safety of the battery cell.

[0008] In addition, the arc design of the first and second arc grooves shortens the path of the pressure relief section along the groove, thereby enabling the pressure relief section to open quickly, achieving rapid pressure relief, improving pressure relief efficiency, reducing the risk of fire and explosion of battery cells due to thermal runaway, and improving the safety of battery cells.

[0009] In some embodiments, the groove further includes a first groove extending along the second direction, and the first arcuate groove is connected to the second arcuate groove through the first groove.

[0010] In the above technical solution, the groove also includes a first groove extending along the second direction and connected between the first arc-shaped groove and the second arc-shaped groove. The setting of the first groove increases the distance between the first arc-shaped groove and the second arc-shaped groove, thereby increasing the size of the pressure relief part in the second direction, increasing the opening area of ​​the pressure relief part, increasing the pressure relief area of ​​the pressure relief device, and thus improving the pressure relief efficiency of the pressure relief device.

[0011] In some embodiments, both the first arcuate groove and the second arcuate groove are tangent to the first groove.

[0012] In the above technical solution, both the first arc-shaped groove and the second arc-shaped groove are tangent to the first groove, eliminating the sharp corners at the connection positions of the first arc-shaped groove and the first groove, avoiding stress concentration, and improving the stability of the pressure relief device before pressure relief.

[0013] In some embodiments, one end of the first arcuate groove away from the second opening side is connected to one end of the second arcuate groove away from the third opening side.

[0014] In the above technical solution, one end of the first arc-shaped groove is directly connected to one end of the second arc-shaped groove, which simplifies the structure of the scoring groove and reduces production costs.

[0015] In some embodiments, the groove further includes a second groove and a third groove; the second groove extends from one end of the first arcuate groove away from the second arcuate groove in a direction away from the first opening side, and the third groove extends from one end of the second arcuate groove away from the first arcuate groove in a direction away from the first opening side.

[0016] In the above technical solution, the setting of the second and third grooves increases the size of the pressure relief part in the first direction, increases the opening area of ​​the pressure relief part, increases the pressure relief area of ​​the pressure relief device, and thus improves the pressure relief efficiency of the pressure relief device.

[0017] In some embodiments, the second groove is tangent to the first arc-shaped groove, and the third groove is tangent to the second arc-shaped groove.

[0018] In the above technical solution, the second groove is tangent to the first arc-shaped groove, eliminating the sharp corner at the connection between the second groove and the first arc-shaped groove; the third groove is tangent to the second arc-shaped groove, eliminating the sharp corner at the connection between the third groove and the second arc-shaped groove, thus avoiding stress concentration and improving the stability of the pressure relief device before pressure relief.

[0019] In some embodiments, both the second groove and the third groove extend along the first direction.

[0020] In the above technical solution, both the second and third grooves extend along the first direction, so that the second and third grooves are arranged in parallel, which allows the pressure relief part to open more regularly when depressurizing, which is beneficial to the pressure relief device.

[0021] In some embodiments, in the second direction, the first arc-shaped groove and the second arc-shaped groove are symmetrically distributed on the pressure relief body.

[0022] In the above technical solution, the first arc-shaped groove and the second arc-shaped groove are symmetrically distributed on the pressure relief body, which is beneficial for the pressure relief part to simultaneously open from the first opening side along the first arc-shaped groove and the second arc-shaped groove to the second opening side and the third opening side, thereby improving the opening efficiency of the pressure relief part.

[0023] In some embodiments, the pressure relief body includes: a receiving space for receiving the electrode assembly of the battery cell, a wall defining the receiving space, and the groove being disposed on the inner or outer surface of the wall.

[0024] In the above technical solution, the pressure relief body includes a receiving space defined by a wall, which can accommodate the electrode assembly, so that the pressure relief device has both pressure relief function and the function of accommodating the electrode assembly.

[0025] In some embodiments, the wall includes a peripheral wall, which is a hollow structure open at both ends in its extending direction; the groove is disposed on the inner or outer surface of the peripheral wall.

[0026] In the above technical solution, the scoring groove is set on the peripheral wall, which can provide a larger setting space for the scoring groove, which is conducive to forming a large-sized pressure relief part on the peripheral wall and ensuring the pressure relief area of ​​the pressure relief part.

[0027] In some embodiments, the peripheral wall is a cylinder, and the angle between the extending direction of the peripheral wall and the second direction is less than 45 degrees.

[0028] In the above technical solution, the peripheral wall is cylindrical, and the larger the angle between the groove and the extension direction of the peripheral wall, the less likely it is to break. The angle between the extension direction of the peripheral wall and the second direction is less than 45 degrees, which makes the difficulty of breaking the first arc groove gradually increase from the first opening side to the second opening side, and the difficulty of breaking the second arc groove gradually increase from the second opening side to the third opening side, ensuring that the pressure relief part opens first from the first opening side.

[0029] In some embodiments, the extension direction of the peripheral wall is consistent with the second direction.

[0030] In the above technical solution, the extension direction of the peripheral wall is consistent with the second direction, further ensuring that the pressure relief part opens first from the first opening side.

[0031] In some embodiments, the wall is provided with a set of grooves, the set of grooves including two grooves spaced apart along the first direction, the first opening side of the pressure relief portion defined by one groove of the set of grooves being disposed opposite to the first opening side of the pressure relief portion defined by the other groove.

[0032] In the above technical solution, the first opening side of the pressure relief part defined by one groove in the groove group and the first opening side of the pressure relief part defined by the other groove are arranged back to back, so that the two pressure relief parts defined by the two grooves are arranged back to back. During the pressure relief process, the two pressure relief parts will open back to back, increasing the pressure relief area.

[0033] In some embodiments, the wall includes a peripheral wall, which is a hollow structure open at both ends in its extending direction, and a plurality of said groove groups are provided on the peripheral wall at circumferential intervals.

[0034] In the above technical solution, the peripheral wall is provided with multiple sets of grooves spaced apart along its axial direction. Each set of grooves can be used for pressure relief, enabling the pressure relief device to relieve pressure from multiple directions and improve pressure relief efficiency. Even if a set of grooves in one direction is blocked by other components, the pressure relief part defined by the set of grooves in other directions can still be opened to relieve pressure.

[0035] Secondly, embodiments of this application provide a battery cell including the pressure relief device provided in any one of the embodiments of the first aspect.

[0036] Thirdly, embodiments of this application provide a battery, including: a battery cell provided in any one of the embodiments of the second aspect; and a housing for accommodating the battery cell.

[0037] Fourthly, embodiments of this application provide an electrical device including the battery provided in any one of the embodiments of the third aspect.

[0038] Fifthly, embodiments of this application provide a method for manufacturing a pressure relief device, the method comprising: providing a pressure relief body; machining a groove on the pressure relief body; wherein the groove defines a pressure relief portion, the pressure relief portion being configured to open when the internal pressure or temperature of a battery cell reaches a threshold, thereby releasing the internal pressure of the battery cell, the pressure relief portion forming a first opening side on one side in a first direction, and forming a second opening side and a third opening side on both sides in a second direction, the first direction being perpendicular to the second direction, the groove including a first arcuate groove and a second arcuate groove, the first arcuate groove extending from the first opening side to the second opening side, and the second arcuate groove extending from the first opening side to the third opening side.

[0039] In a sixth aspect, embodiments of this application also provide a manufacturing apparatus for a pressure relief device, the manufacturing apparatus comprising: a providing device for providing a pressure relief body; and a processing device for processing a groove on the pressure relief body; wherein the groove defines a pressure relief portion, the pressure relief portion being configured to open when the internal pressure or temperature of a battery cell reaches a threshold, thereby releasing the internal pressure of the battery cell, the pressure relief portion forming a first opening side on one side in a first direction, and forming a second opening side and a third opening side on both sides in a second direction, the first direction being perpendicular to the second direction, the groove including a first arcuate groove and a second arcuate groove, the first arcuate groove extending from the first opening side to the second opening side, and the second arcuate groove extending from the first opening side to the third opening side. Attached Figure Description

[0040] 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.

[0041] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0042] Figure 2 This application provides schematic diagrams of the battery structure for some embodiments.

[0043] Figure 3 Exploded views of a single battery cell provided in some embodiments of this application;

[0044] Figure 4 Partial views of pressure relief devices provided in some embodiments of this application;

[0045] Figure 5A partial view of a pressure relief device provided in some embodiments of this application;

[0046] Figure 6 A partial view of a pressure relief device provided in some embodiments of this application;

[0047] Figure 7 This is a schematic diagram of the structure of a pressure relief device provided in some embodiments of this application;

[0048] Figure 8 Flowcharts illustrating methods for manufacturing pressure relief devices provided in some embodiments of this application;

[0049] Figure 9 A schematic block diagram of a manufacturing apparatus for a pressure relief device provided in some embodiments of this application.

[0050] Icons: 10-Box; 11-First part; 12-Second part; 20-Battery cell; 21-Housing shell; 22-Electrode assembly; 23-End cap; 24-Pressure relief device; 241-Pressure relief body; 2411-Pressure relief section; 2411a-First opening side; 2411b-Second opening side; 2411c-Third opening side; 2412-Accommodation space; 2413-Peripheral wall; 242-Score groove; 2421-First arc-shaped groove; 2422-Second arc-shaped groove; 2423-First groove; 2424-Second groove; 2425-Third groove; 243-Score group; 25-Electrode terminal; 26-Current collector; 100-Battery; 200-Controller; 300-Motor; 1000-Vehicle; 2000-Manufacturing equipment; 2100-Providing device; 2200-Processing device; X-First direction; Y-Second direction. Detailed Implementation

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0055] 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.

[0056] In this application, "multiple" means two or more (including two).

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] In order to ensure the safety of a battery cell, a pressure relief device is usually installed in the battery cell to release the internal pressure and ensure the safety of the battery cell.

[0062] The inventors discovered that even with pressure relief devices installed in individual battery cells, the risk of cell fire and explosion still exists. Further research revealed that current pressure relief devices typically involve grooves on the relief body. During pressure relief, the relief section of the body splits open at the groove to release internal contaminants from the battery cell. However, these grooves consist of multiple segments in different locations, with right-angle transitions between segments. This can lead to a situation where, after one segment of the relief section splits, it doesn't continue splitting along other segments, resulting in insufficient opening of the relief section. This low pressure relief efficiency means that in the event of thermal runaway, internal contaminants cannot be released in time, potentially leading to fire or explosion, posing a safety hazard.

[0063] In view of this, the present application provides a pressure relief device, which provides a groove on the pressure relief body, the groove defining a pressure relief part, a first opening side is formed on one side in a first direction, and a second opening side and a third opening side are formed on both sides in a second direction, the first direction being perpendicular to the second direction, wherein the groove includes a first arc-shaped groove and a second arc-shaped groove, the first arc-shaped groove extending from the first opening side to the second opening side, and the second arc-shaped groove extending from the first opening side to the third opening side.

[0064] In such a pressure relief device, the arc-shaped design of the first and second arc-shaped grooves in the groove allows the pressure relief section to smoothly open from the first opening side to the second and third opening sides respectively along the first and second arc-shaped grooves during the opening process. The pressure relief section has a large pressure relief area, making it less likely that the pressure relief section cannot be opened over a large area, thus improving the safety of the battery cell.

[0065] The technical solutions described in the embodiments of this application are applicable to battery cells, batteries, and electrical devices that use batteries.

[0066] 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.

[0067] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0068] 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, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] The housing 10 is a component that houses the battery cell 20, providing a cavity for the battery cell 20. The housing 10 can adopt 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 cavity for housing 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 cavity. 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 cavity. The first part 11 and the second part 12 can be sealed using a sealing element, such as a sealing ring or sealant.

[0073] 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.

[0074] 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.

[0075] 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, and a pressure relief device 24.

[0076] 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, or it can be a hollow structure with openings at both opposite ends. If the housing 21 is a hollow structure with an opening at one end, one end cap 23 can be correspondingly provided; if the housing 21 is a hollow structure with openings at both ends, two end caps 23 can be provided, each covering the opening at one end of the housing 21. The housing 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The housing 21 can also be in various shapes, such as a cylinder or a cuboid. Figure 3 In the middle, the shell 21 is a cylinder and a hollow structure with an opening at one end.

[0077] Electrode assembly 22 is the component in the battery cell 20 where the electrochemical reaction takes place. Electrode assembly 22 can be a cylinder, cuboid, etc. If electrode assembly 22 is a cylinder, housing 21 can also be a cylinder; if electrode assembly 22 is a cuboid, housing 21 can also be a cuboid.

[0078] The electrode assembly 22 may include a positive electrode, a negative electrode, and a separator. The 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. 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 positive and negative electrode tabs; the positive electrode tab may be a portion of the positive electrode that is not coated with the positive active material layer, and the negative electrode tab may be a portion of the negative electrode that is not coated with the negative active material layer.

[0079] 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 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.

[0080] Electrode terminals 25 can be provided on the end cap 23. Electrode terminals 25 are used for electrical connection with the positive or negative electrode tab of the electrode assembly 22.

[0081] In some embodiments, the battery cell 20 may further include a current collector 26, and the electrode terminal 25 is electrically connected to the positive or negative electrode tab of the electrode assembly 22 through the current collector 26.

[0082] The current collector 26 of the battery cell 20 can be one or two. For example, the housing 21 is a hollow structure with an opening at one end, and the end cap 23 covers the opening of the housing 21. One of the positive electrode tabs and the negative electrode tabs is electrically connected to the electrode terminal 25 through one current collector 26, and the other is electrically connected to the housing 21. Alternatively, the housing 21 is a hollow structure with openings at opposite ends, and two end caps 23 cover the two openings of the housing 21 respectively. One of the positive electrode tabs and the negative electrode tabs is electrically connected to the electrode terminal 25 on one end cap 23 through one current collector 26, and the other is electrically connected to the electrode terminal 25 on the other end cap 23 through another current collector 26.

[0083] The pressure relief device 24 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 24. The specific structure of the pressure relief device 24 is described in detail below with reference to the accompanying drawings.

[0084] Please refer to Figure 4 and Figure 5 , Figure 4 This is a partial view of the pressure relief device 24 provided in some embodiments of this application. Figure 5 This is a partial view of a pressure relief device 24 provided in some embodiments of this application. The pressure relief device 24 is used for a battery cell 20 and includes a pressure relief body 241 and a groove 242. The pressure relief body 241 includes a pressure relief portion 2411, which is configured to open when the internal pressure or temperature of the battery cell 20 reaches a threshold to release the internal pressure of the battery cell 20. The pressure relief portion 2411 forms a first opening side 2411a on one side in a first direction X, and a second opening side 2411b and a third opening side 2411c on both sides in a second direction Y, respectively. The first direction X is perpendicular to the second direction Y. A groove 242 is provided on the pressure relief body 241, and the groove 242 defines a pressure relief part 2411. The groove 242 includes a first arc-shaped groove 2421 and a second arc-shaped groove 2422. The first arc-shaped groove 2421 extends from the first opening side 2411a to the second opening side 2411b, and the second arc-shaped groove 2422 extends from the first opening side 2411a to the third opening side 2411c.

[0085] The pressure relief device 24 can be a component mounted on the end cap 23 or on the housing 21, such as an explosion-proof valve or explosion-proof plate. The pressure relief device 24 can also form the housing 21 of the battery cell 20, in which case the pressure relief device 24 is the housing 21 used to accommodate the electrode assembly 22. In this case, the groove 242 is provided on the housing 21. Of course, the groove 242 can be provided on the outer surface of the housing 21 or on the inner surface of the housing 21.

[0086] The first direction X and the second direction Y are perpendicular to each other. In embodiments where the pressure relief device 24 has a sheet-like structure, such as an explosion-proof sheet, one of the first direction X and the second direction Y can be the length direction of the pressure relief device 24, and the other can be the width direction of the pressure relief device 24. In embodiments where the pressure relief device 24 is a housing 21, one of the first direction X and the second direction Y can be the circumferential direction of the housing 21, and the other can be the axial direction of the housing 21.

[0087] The pressure relief section 2411 is the area defined by the groove 242 of the pressure relief body 241. The groove 242 is located at the edge of the pressure relief section 2411. During pressure relief, the pressure relief section 2411 will open with the groove 242 as the boundary. During the process of the pressure relief body 241 cracking at the location of the groove 242, the pressure relief section 2411 can be opened by flipping to achieve pressure relief. The pressure relief section 2411 has a first opening side 2411a on one side in the first direction X, and a second opening side 2411b and a third opening side 2411c on opposite sides in the second direction Y, that is, the pressure relief section 2411 has three opening sides with different orientations.

[0088] The groove 242 can be formed on the pressure relief body 241 in various ways, such as by stamping or milling. The groove 242 can have various shapes, such as a "U" shape or a "C" shape. The first arc-shaped groove 2421 and the second arc-shaped groove 2422 can be arc-shaped structures, and their radii can be equal or unequal. The first arc-shaped groove 2421 and the second arc-shaped groove 2422 can be directly connected or indirectly connected.

[0089] In the pressure relief device 24, the groove 242 on the pressure relief body 241 defines the pressure relief part 2411. When the internal pressure or temperature of the battery cell 20 reaches a threshold, the pressure relief part 2411 will open with the groove 242 as the boundary. Because the first arc-shaped groove 2421 of the groove 242 extends from the first opening side 2411a to the second opening side 2411b, and the second arc-shaped groove 2422 extends from the first opening side 2411a to the third opening side 2411c, the arc-shaped design of the first arc-shaped groove 2421 and the second arc-shaped groove 2422 allows the pressure relief part 2411 to smoothly open from the first opening side 2411a along the first arc-shaped groove 2421 and the second arc-shaped groove 2422 to the second opening side 2411b and the third opening side 2411c respectively during the opening process of the pressure relief part 2411. The pressure relief part 2411 has a large pressure relief area, making it less likely that the pressure relief part 2411 will not be able to open over a large area, thus improving the safety of the battery cell 20.

[0090] Furthermore, the arc-shaped design of the first arc-shaped groove 2421 and the second arc-shaped groove 2422 shortens the path of the pressure relief part 2411 as it splits along the groove 242, thereby enabling the pressure relief part 2411 to open quickly, achieving rapid pressure relief, improving pressure relief efficiency, reducing the risk of fire and explosion of the battery cell 20 due to thermal runaway, and improving the safety of the battery cell 20.

[0091] In some embodiments, please continue to refer to Figure 5The groove 242 may also include a first groove 2423, which extends along the second direction Y, and the first arc groove 2421 is connected to the second arc groove 2422 through the first groove 2423.

[0092] The first groove 2423 extends along the second direction Y, and the second opening side 2411b and the third opening side 2411c of the pressure relief part 2411 are arranged opposite to each other in the extension direction of the first groove 2423. The first groove 2423 serves to connect the first arc-shaped groove 2421 and the second arc-shaped groove 2422, and the first groove 2423 is located on the first opening side 2411a of the pressure relief part 2411. The width of the first groove 2423 can be the same as the width of the first arc-shaped groove 2421 and the second arc-shaped groove 2422, and the depth of the first groove 2423 can be equal to or greater than the depth of the first arc-shaped groove 2421 and the second arc-shaped groove 2422. In actual processing, the first arc-shaped groove 2421, the first groove 2423, and the second arc-shaped groove 2422 can be formed in one step.

[0093] The location of the first groove 2423 is the first point where the pressure relief body 241 will break. In other words, when the internal pressure or temperature of the battery cell 20 reaches the threshold, the pressure relief body 241 will break first at the location of the first groove 2423, and then break along the first arc groove 2421 and the second arc groove 2422.

[0094] In this embodiment, since the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are connected by the first groove 2423, the arrangement of the first groove 2423 increases the distance between the first arc-shaped groove 2421 and the second arc-shaped groove 2422, thereby increasing the size of the pressure relief part 2411 in the second direction Y, increasing the opening area of ​​the pressure relief part 2411, increasing the pressure relief area of ​​the pressure relief device 24, and thus improving the pressure relief efficiency of the pressure relief device 24.

[0095] Please continue to refer to Figure 5 In some embodiments, the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are both tangent to the first groove 2423.

[0096] The first arc-shaped groove 2421 and the second arc-shaped groove 2422 are both tangent to the first groove 2423, eliminating the sharp corners at the connection positions of the first arc-shaped groove 2421 and the first groove 2423, as well as the connection positions of the second arc-shaped groove 2422 and the first groove 2423, thus avoiding stress concentration and improving the stability of the pressure relief device 24 before pressure relief.

[0097] In some embodiments, please continue to refer to Figure 4 The end of the first arc-shaped groove 2421 away from the second opening side 2411b is connected to the end of the second arc-shaped groove 2422 away from the third opening side 2411c.

[0098] The radii of the first arc-shaped groove 2421 and the second arc-shaped groove 2422 can be equal or unequal. When the radii of the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are equal, the first arc-shaped groove 2421 and the second arc-shaped groove 2422 can be located on the same circumference, that is, the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are concentrically arranged.

[0099] In this embodiment, the end of the first arc-shaped groove 2421 away from the second opening side 2411b is connected to the end of the second arc-shaped groove 2422 away from the third opening groove, that is, the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are directly connected, which simplifies the structure of the scoring groove 242 and reduces production costs.

[0100] In some embodiments, please refer to Figure 6 , Figure 6 This is a partial view of the pressure relief device 24 provided in some embodiments of the present application. The groove 242 may also include a second groove 2424 and a third groove 2425. The second groove 2424 extends from the end of the first arcuate groove 2421 away from the second arcuate groove 2422 in a direction away from the first opening side 2411a. The third groove 2425 extends from the end of the second arcuate groove 2422 away from the first arcuate groove 2421 in a direction away from the first opening side 2411a.

[0101] The second groove 2424 and the third groove 2425 are located on the second opening side 2411b and the third opening side 2411c of the pressure relief section 2411, respectively. The first groove 2423 and the second groove 2424 can be arranged in parallel. The first groove 2423 and the second groove 2424 can also be arranged at a non-zero angle, for example, the distance between the first groove 2423 and the second groove 2424 gradually increases from a position closer to the first opening side 2411a to a position farther away from the first opening side 2411a. The length of the second groove 2424 and the length of the third groove 2425 can be equal or unequal.

[0102] It should be noted that regardless of whether the first arc groove 2421 and the second arc groove 2422 are directly connected or indirectly connected (for example, the first arc groove 2421 and the second arc groove 2422 are connected through the first groove 2423), the groove 242 can include the second groove 2424 and the third groove 2425.

[0103] In this embodiment, the arrangement of the second groove 2424 and the third groove 2425 increases the size of the pressure relief part 2411 in the first direction X, increases the opening area of ​​the pressure relief part 2411, increases the pressure relief area of ​​the pressure relief device 24, and thus improves the pressure relief efficiency of the pressure relief device 24.

[0104] In some embodiments, the second groove 2424 is tangent to the first arc-shaped groove 2421, and the third groove 2425 is tangent to the second arc-shaped groove 2422.

[0105] The second groove 2424 is tangent to the first arc-shaped groove 2421, eliminating the sharp angle at the connection between the second groove 2424 and the first arc-shaped groove 2421. The third groove 2425 is tangent to the second arc-shaped groove 2422, eliminating the sharp angle at the connection between the third groove 2425 and the second arc-shaped groove 2422, thus avoiding stress concentration and improving the stability of the pressure relief device 24 before pressure relief.

[0106] Please continue to refer to Figure 6 In the embodiment where both the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are tangent to the first groove 2423, since the second groove 2424 is tangent to the first arc-shaped groove 2421 and the third groove 2425 is tangent to the second arc-shaped groove 2422, the first groove 2423 smoothly transitions to the second groove 2424 through the first arc-shaped groove 2421, and the first groove 2423 smoothly transitions to the third groove 2425 through the second arc-shaped groove 2422. During the opening of the pressure relief part 2411, the pressure relief part 2411 can more smoothly split from the first groove 2423 along the first arc-shaped groove 2421 and the second arc-shaped groove 2422 towards the second groove 2424 and the third groove 2425, respectively.

[0107] In some embodiments, both the second groove 2424 and the third groove 2425 extend along the first direction X. That is, the second groove 2424 and the third groove 2425 are arranged in parallel, so that the pressure relief section 2411 can open more regularly when pressure is relieved, which is beneficial to the pressure relief device 24.

[0108] For example, the length of the second groove 2424 is equal to the length of the third groove 2425, so that the crack length of the pressure relief part 2411 on the second opening side 2411b is equal to the crack length of the pressure relief part 2411 on the third opening side 2411c, so that the pressure relief part 2411 can open more regularly when relieving pressure.

[0109] In some embodiments, please refer to Figures 4-6 In the second direction Y, the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are symmetrically distributed on the pressure relief body 241.

[0110] The first arc-shaped groove 2421 and the second arc-shaped groove 2422 are symmetrically distributed in the second direction Y, that is, the axis of symmetry of the first arc-shaped groove 2421 and the second arc-shaped groove 2422 extends along the first direction X.

[0111] Since the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are symmetrically distributed on the pressure relief body 241, it is beneficial for the pressure relief part 2411 to simultaneously open from the first opening side 2411a along the first arc-shaped groove 2421 and the second arc-shaped groove 2422 to the second opening side 2411b and the third opening side 2411c, thereby improving the opening efficiency of the pressure relief part 2411.

[0112] In some embodiments, please refer to Figure 7 , Figure 7 The following is a schematic diagram of the structure of the pressure relief device 24 provided in some embodiments of this application. The pressure relief body 241 includes a receiving space 2412 and a wall. The receiving space 2412 is used to receive the electrode assembly 22 of the battery cell 20. The wall defines the receiving space 2412. The groove 242 is provided on the inner or outer surface of the wall.

[0113] The wall of the pressure relief body 241 defines a receiving space 2412 for accommodating the electrode assembly 22, and the pressure relief device 24 forms the housing 21 of the battery cell 20. The wall of the pressure relief body 241 can be of various shapes, such as a cylinder or a cuboid. The wall can have one opening or two openings. If the wall has only one opening, the end cap 23 of the battery cell 20 is one; if the wall has two opposing openings, the end cap 23 of the battery cell 20 can be provided accordingly.

[0114] In this embodiment, the pressure relief body 241 includes a receiving space 2412 defined by a wall. The receiving space 2412 can accommodate the electrode assembly 22, so that the pressure relief device 24 has both pressure relief function and the function of accommodating the electrode assembly 22.

[0115] In some embodiments, the wall of the pressure relief body 241 includes a peripheral wall 2413, which is a hollow structure with open ends in its extending direction; a groove 242 is provided on the inner or outer surface of the peripheral wall 2413.

[0116] The wall of the pressure relief body 241 may consist only of a peripheral wall 2413, or it may include a bottom wall in addition to the peripheral wall 2413. If the wall of the pressure relief body 241 consists only of a peripheral wall 2413, the pressure relief body 241 is a hollow structure with openings at both ends, and the shell 21 is also a hollow structure with openings at both ends. If the wall of the pressure relief body 241 also includes a bottom wall, the bottom wall can block the opening at one end of the peripheral wall 2413, making the pressure relief body 241 a hollow structure with an opening at one end, and the shell 21 is also a hollow structure with an opening at one end. The peripheral wall 2413 may be a stamped or drawn part.

[0117] For a typical battery cell 20, the groove 242 is set on the bottom wall of the housing 21 or on the end cap 23. The size of the groove 242 is limited by the bottom wall or end cap 23. The space provided by the bottom wall or end cap 23 for the groove 242 is limited, resulting in poor pressure relief.

[0118] In this embodiment, since the groove 242 is provided on the peripheral wall 2413, the peripheral wall 2413 can provide a larger space for the groove 242, which is conducive to forming a large pressure relief part 2411 on the peripheral wall 2413 and ensuring the pressure relief area of ​​the pressure relief part 2411.

[0119] In some embodiments, please continue to refer to Figure 7 The peripheral wall 2413 is a cylinder, and the angle between the extension direction of the peripheral wall 2413 and the second direction Y is less than 45 degrees.

[0120] Since the peripheral wall 2413 is a cylinder, the extension direction of the peripheral wall 2413 is its axial direction. In the embodiment where the groove 242 includes a first groove 2423, since the first groove 2423 extends along the second direction Y, and the angle between the extension direction of the peripheral wall 2413 and the second direction Y is less than 45 degrees, it can be understood that the angle between the extension direction of the peripheral wall 2413 and the first groove 2423 is less than 45 degrees.

[0121] The peripheral wall 2413 is cylindrical. The larger the angle between the groove 242 and the extension direction of the peripheral wall 2413, the less likely it is to break. The angle between the extension direction of the peripheral wall 2413 and the second direction Y is less than 45 degrees, which makes the difficulty of breaking the first arc groove gradually increase from the first opening side 2411a to the second opening side 2411b, and the difficulty of breaking the second arc groove gradually increase from the second opening side 2411b to the third opening side 2411c, ensuring that the pressure relief part 2411 opens first from the first opening side 2411a.

[0122] In some embodiments, the extension direction of the peripheral wall 2413 is consistent with the second direction Y, further ensuring that the pressure relief section 2411 opens first from the first opening side 2411a.

[0123] The extension direction of the peripheral wall 2413 is consistent with the second direction Y. It can also be understood that the angle between the extension direction of the peripheral wall 2413 and the second direction Y is 0 degrees. The first direction X is the circumferential direction of the peripheral wall 2413.

[0124] In the embodiment where the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are directly connected, the connection point between the first arc-shaped groove 2421 and the second arc-shaped groove 2422 is located on the first opening side 2411a. Since the peripheral wall 2413 is cylindrical, the pressure relief body 241 is most prone to breakage at the position adjacent to the first arc-shaped groove 2421 and the second arc-shaped groove 2422. In the embodiment where the first arc-shaped groove 2421 and the second arc-shaped groove 2422 are indirectly connected through the first groove 2423, the extending direction of the first groove 2423 is consistent with the extending direction of the peripheral wall 2413. Since the peripheral wall 2413 is cylindrical, the smaller the angle between the extended direction of the groove 242 and the peripheral wall 2413, the more prone it is to breakage. Therefore, the pressure relief body 241 is most prone to breakage at the position of the first groove 2423. Furthermore, since the peripheral wall 2413 is a cylinder, the pressure relief part 2411 defined by the groove 242 is in a bent state due to the bending of the peripheral wall 2413. The pressure relief part 2411 has a tendency to recover its deformation, which is more conducive to opening the pressure relief part 2411 during the cracking process along the groove 242.

[0125] In some embodiments, please continue to refer to Figure 7 The pressure relief body 241 has a groove group 243 on its wall. The groove group 243 includes two grooves 242 spaced apart along the first direction X. The first opening side 2411a of the pressure relief part 2411 defined by one groove 242 of the groove group 243 is arranged back to back with the first opening side 2411a of the pressure relief part 2411 defined by the other groove 242.

[0126] In this embodiment, since the first opening side 2411a of the pressure relief part 2411 defined by one groove 242 in the groove group 243 and the first opening side 2411a of the pressure relief part 2411 defined by the other groove 242 are arranged back to back, the two pressure relief parts 2411 defined by the two grooves 242 are arranged back to back. During the pressure relief process, the two pressure relief parts 2411 will open back to back, increasing the pressure relief area.

[0127] In some embodiments, please continue to refer to Figure 7 The wall of the pressure relief body 241 includes a peripheral wall 2413, which is a hollow structure with open ends in its extension direction. Multiple groove groups 243 are provided on the peripheral wall 2413 at intervals along its circumference.

[0128] In the extending direction of the peripheral wall 2413, the groove group 243 on the peripheral wall 2413 can be one row or multiple rows, and each row of groove group 243 includes multiple groove groups 243 arranged circumferentially along the peripheral wall 2413. The groove 242 in the groove group 243 can be provided on the outer surface of the peripheral wall 2413 or on the inner surface of the peripheral wall 2413. For example, in Figure 7In the direction of the extension of the peripheral wall 2413, two rows of engravings are provided on the outer surface of the peripheral wall.

[0129] In this embodiment, since the peripheral wall 2413 is provided with multiple sets of grooves 243 spaced apart along its axial direction, each set of grooves 243 can be used for pressure relief, enabling the pressure relief device 24 to relieve pressure from multiple directions and improve pressure relief efficiency. Even if the set of grooves 243 in one direction is blocked by other components, the pressure relief portion 2411 defined by the set of grooves 243 in other directions of the pressure relief device 24 can still be opened to relieve pressure.

[0130] It should be noted that in embodiments where the wall of the pressure relief body 241 also includes a bottom wall connected to the peripheral wall 2413, the scoring group 243 may also be provided on the bottom wall.

[0131] This application provides a battery cell 20, including the pressure relief device 24 provided in any of the above embodiments.

[0132] This application provides a battery 100, including a housing 10 and a battery cell 20 provided in any of the above embodiments, wherein the housing 10 is used to accommodate the battery cell 20.

[0133] This application provides an electrical device, including the battery 100 provided in any of the above embodiments.

[0134] The electrical equipment can be any of the devices that use battery 100 as described above.

[0135] Please refer to Figure 7 This application provides a cylindrical shell for accommodating an electrode assembly 22. The cylindrical shell is provided with a groove 242, which defines a pressure relief portion 2411. The pressure relief portion 2411 forms a first opening side 2411a on one side in a first direction X, and a second opening side 2411b and a third opening side 2411c on both sides in a second direction Y, respectively. The first direction X is perpendicular to the second direction Y. The groove 242 includes a first arcuate groove 2421 and a second arcuate groove 2422. The first arcuate groove 2421 extends from the first opening side 2411a to the second opening side 2411b, and the second arcuate groove 2422 extends from the first opening side 2411a to the third opening side 2411c. The arc-shaped design of the first arc-shaped groove 2421 and the second arc-shaped groove 2422 allows the pressure relief section 2411 to smoothly open from the first opening side 2411a along the first arc-shaped groove 2421 and the second arc-shaped groove 2422 to the second opening side 2411b and the third opening side 2411c, respectively. The pressure relief section 2411 has a large pressure relief area, making it less likely that the pressure relief section 2411 will not be able to open over a large area, thus improving the safety of the battery cell 20.

[0136] This application provides a method for manufacturing a pressure relief device 24. Please refer to... Figure 8 , Figure 8 A flowchart illustrating a method for manufacturing a pressure relief device 24 provided in some embodiments of this application, the method comprising:

[0137] S100: Provides pressure relief body 241;

[0138] S200: A groove 242 is machined on the pressure relief body 241.

[0139] The groove 242 defines a pressure relief section 2411, which is configured to open when the internal pressure or temperature of the battery cell 20 reaches a threshold to release the internal pressure of the battery cell 20. The pressure relief section 2411 forms a first opening side 2411a on one side in the first direction X, and a second opening side 2411b and a third opening side 2411c on both sides in the second direction Y, respectively. The first direction X is perpendicular to the second direction Y. The groove 242 includes a first arcuate groove 2421 and a second arcuate groove 2422. The first arcuate groove 2421 extends from the first opening side 2411a to the second opening side 2411b, and the second arcuate groove 2422 extends from the first opening side 2411a to the third opening side 2411c.

[0140] It should be noted that the relevant structure of the pressure relief device 24 manufactured by the manufacturing method provided in the above embodiments can be found in the pressure relief device 24 provided in the foregoing embodiments, and will not be described again here.

[0141] This application embodiment also provides a manufacturing apparatus 2000 for a pressure relief device 24, please refer to... Figure 9 , Figure 9 This is a schematic block diagram of a manufacturing apparatus 2000 for a pressure relief device 24 provided in some embodiments of this application. The manufacturing apparatus 2000 includes a providing device 2100 and a processing device 2200. The providing device 2100 is used to provide a pressure relief body 241, and the processing device 2200 is used to process a groove 242 on the pressure relief body 241.

[0142] The groove 242 defines a pressure relief section 2411, which is configured to open when the internal pressure or temperature of the battery cell 20 reaches a threshold to release the internal pressure of the battery cell 20. The pressure relief section 2411 forms a first opening side 2411a on one side in the first direction X, and a second opening side 2411b and a third opening side 2411c on both sides in the second direction Y, respectively. The first direction X is perpendicular to the second direction Y. The groove 242 includes a first arcuate groove 2421 and a second arcuate groove 2422. The first arcuate groove 2421 extends from the first opening side 2411a to the second opening side 2411b, and the second arcuate groove 2422 extends from the first opening side 2411a to the third opening side 2411c.

[0143] It should be noted that the relevant structure of the pressure relief device 24 manufactured by the manufacturing equipment 2000 provided in the above embodiments can be found in the pressure relief device 24 provided in the foregoing embodiments, and will not be described again here.

[0144] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0145] 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 for a single battery cell, characterized in that, include: The pressure relief body includes a pressure relief section, which is configured to open when the internal pressure or temperature of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell. The pressure relief section forms a first opening side on one side in a first direction, and forms a second opening side and a third opening side on both sides in a second direction, respectively. The first direction is perpendicular to the second direction. A groove is provided on the pressure relief body, the groove defines the pressure relief part, the groove includes a first arc groove and a second arc groove, the first arc groove extends from the first opening side to the second opening side, and the second arc groove extends from the first opening side to the third opening side. The pressure relief body includes a receiving space and a wall. The receiving space is used to receive the electrode assembly of the battery cell. The wall defines the receiving space. The wall includes a peripheral wall, which is a hollow structure with open ends in its extending direction. The peripheral wall is a cylinder. The groove is provided on the inner or outer surface of the peripheral wall.

2. The pressure relief device according to claim 1, characterized in that, The groove also includes a first groove that extends along the second direction, and the first arc-shaped groove is connected to the second arc-shaped groove through the first groove.

3. The pressure relief device according to claim 2, characterized in that, Both the first arc-shaped groove and the second arc-shaped groove are tangent to the first groove.

4. The pressure relief device according to claim 1, characterized in that, The end of the first arc-shaped groove away from the second opening side is connected to the end of the second arc-shaped groove away from the third opening side.

5. The pressure relief device according to claim 1, characterized in that, The groove also includes a second groove and a third groove; The second groove extends from the end of the first arc-shaped groove away from the second arc-shaped groove in a direction away from the first opening side, and the third groove extends from the end of the second arc-shaped groove away from the first arc-shaped groove in a direction away from the first opening side.

6. The pressure relief device according to claim 5, characterized in that, The second groove is tangent to the first arc-shaped groove, and the third groove is tangent to the second arc-shaped groove.

7. The pressure relief device according to claim 5, characterized in that, Both the second groove and the third groove extend along the first direction.

8. The pressure relief device according to claim 1, characterized in that, In the second direction, the first arc-shaped groove and the second arc-shaped groove are symmetrically distributed on the pressure relief body.

9. The pressure relief device according to claim 1, characterized in that, The angle between the extending direction of the peripheral wall and the second direction is less than 45 degrees.

10. The pressure relief device according to claim 1, characterized in that, The extension direction of the peripheral wall is consistent with the second direction.

11. The pressure relief device according to claim 1, characterized in that, The wall is provided with a set of grooves, the set of grooves including two grooves spaced apart along the first direction, the first opening side of the pressure relief part defined by one groove of the set of grooves is arranged opposite to the first opening side of the pressure relief part defined by the other groove.

12. The pressure relief device according to claim 11, characterized in that, The wall includes a peripheral wall, which is a hollow structure with open ends in its extending direction, and a plurality of the aforementioned groove groups are arranged at intervals along its circumference on the peripheral wall.

13. A single battery cell, characterized in that, Includes the pressure relief device according to any one of claims 1-12.

14. A battery, characterized in that, include: The battery cell according to claim 13; as well as The housing is used to house the individual battery cells.

15. An electrical appliance, characterized in that, Includes the battery according to claim 14.

16. A method for manufacturing a pressure relief device, characterized in that, The method includes: Provide a pressure relief body; A groove is machined on the pressure relief body; The groove defines a pressure relief section, which is configured to open when the internal pressure or temperature of the battery cell reaches a threshold to release the internal pressure of the battery cell. The pressure relief section forms a first opening side on one side in a first direction, and a second opening side and a third opening side on both sides in a second direction, respectively. The first direction is perpendicular to the second direction. The groove includes a first arc-shaped groove and a second arc-shaped groove. The first arc-shaped groove extends from the first opening side to the second opening side, and the second arc-shaped groove extends from the first opening side to the third opening side. The pressure relief body includes a receiving space and a wall. The receiving space is used to receive the electrode assembly of the battery cell. The wall defines the receiving space. The wall includes a peripheral wall, which is a hollow structure with open ends in its extending direction. The peripheral wall is a cylinder. The groove is provided on the inner or outer surface of the peripheral wall.

17. A manufacturing equipment for a pressure relief device, characterized in that, The manufacturing equipment includes: a supplying device for supplying the pressure relief body; A machining device is used to machine grooves on the pressure relief body; The groove defines a pressure relief section, which is configured to open when the internal pressure or temperature of the battery cell reaches a threshold to release the internal pressure of the battery cell. The pressure relief section forms a first opening side on one side in a first direction, and a second opening side and a third opening side on both sides in a second direction, respectively. The first direction is perpendicular to the second direction. The groove includes a first arc-shaped groove and a second arc-shaped groove. The first arc-shaped groove extends from the first opening side to the second opening side, and the second arc-shaped groove extends from the first opening side to the third opening side. The pressure relief body includes a receiving space and a wall. The receiving space is used to receive the electrode assembly of the battery cell. The wall defines the receiving space. The wall includes a peripheral wall, which is a hollow structure with open ends in its extending direction. The peripheral wall is a cylinder. The groove is provided on the inner or outer surface of the peripheral wall.

Images