Pressure release member, battery cell, battery and electrical device

Abstract

A pressure release member, a battery cell, a battery, and an electrical device, which belong to the technical field of batteries, wherein the pressure release member includes a mounting fixture and a pressure release valve plate, the mounting fixture having an opening and a countersunk groove including a groove bottom wall and groove side walls that is circumferentially disposed around the opening, the pressure release valve plate being configured to cover the opening and including a main body portion and a mounting portion, the main body portion having a weakened region, the mounting portion being connected to the outer periphery of the main body portion, and the mounting portion being bent so as to be supported by the groove bottom wall and welded to the groove side wall.

Description

[Technical Field]

[0001] Cross-Citation of Related Applications This application is based on and claims priority from a Chinese patent application having application number 202310844856.6 and filing date July 11, 2023, the entire contents of which are hereby incorporated by reference into this application.

[0002] This application relates to the technical field of batteries, and more particularly to pressure relief members, battery cells, batteries, and electrical devices. [Background technology]

[0003] In recent years, new energy vehicles have evolved dramatically, and in the field of electric vehicles, batteries play an irreplaceable and important role as the power source for electric vehicles. As a core component of new energy vehicles, batteries are subject to high reliability requirements. To improve battery reliability, a pressure release mechanism is usually provided in the battery housing, but some pressure release mechanisms have a problem of premature opening, which has been awaiting a solution. Summary of the Invention

[0004] The embodiments of the present application provide a pressure relief member, a battery cell, a battery, and an electric device that can alleviate the problem of the pressure relief valve plate opening before the pressure relief valve plate does.

[0005] In a first aspect, an embodiment of the present application provides a pressure release member for a battery cell, including a mounting fixture and a pressure release valve plate. The mounting fixture has an opening, and the pressure release valve plate is configured to cover the opening. The mounting fixture has a counterbore groove including a groove bottom wall and a groove side wall, which is configured to surround the opening in a circumferential direction. The pressure release valve plate includes a main body portion and a mounting portion, the main body portion having a weakened region, the mounting portion being connected to the outer periphery of the main body portion, and the mounting portion being bent so as to be supported by the groove bottom wall and welded to the groove side wall.

[0006]

[0013] In the above technical aspect, by providing the mounting part on the outer periphery of the main body in a bent shape, stress can be reduced by the bent structure, which improves the adverse effects of welding stress on the weak areas of the pressure relief valve plate during the welding process between the pressure relief valve plate and the mounting fixture, and eliminates the problem of the valve opening prematurely, which is advantageous for improving the accuracy of the valve opening timing during the operation of the pressure relief valve plate, and is further advantageous for improving the vibration-proofing performance of the pressure relief valve plate and improving the stability and reliability of the operation of the pressure relief valve plate. Meanwhile, by supporting the mounting part on the groove bottom wall and welding it to the groove side wall, the groove bottom wall supports the mounting part, which improves the deformation problem during the welding process between the pressure relief valve plate and the mounting fixture, thereby reducing the occurrence of problems such as warpage deformation of the mounting part weld and improving the welding quality, which further improves the stability and reliability of the pressure relief valve plate during the operation of the pressure relief valve plate.

[0007] In some embodiments, the attachment portion includes a cantilever segment, a connecting segment, and a welding segment connected sequentially radially from the inside to the outside of the opening, the connecting segment supported on the groove bottom wall, the cantilever segment cantilevered over the opening and / or countersunk groove, and both the cantilever segment and the welding segment bent relative to the connecting segment toward the groove opening of the countersunk groove, thereby forming a recess between the cantilever segment, the connecting segment, and the welding segment, and the welding segment is welded to the groove side wall.

[0008] In the above technical aspect, by providing the mounting part in the above structural form, it is possible to effectively alleviate the adverse effects of welding stress on the weak areas of the pressure release valve plate, improve the distribution of force acting on the pressure release valve plate during its operation, make the force acting more uniform, improve the vibration-damping and fatigue resistance of the pressure release valve plate, and ultimately improve the reliability and stability of the operation of the pressure release valve plate. In addition, the structure of the mounting part in the above structural form is simple and easy to process.

[0009] In some embodiments, the surface of the connecting segment facing the groove bottom wall includes a first planar segment, and the first planar segment is in surface contact with and supported by the groove bottom wall.

[0010] In the above technical aspect, the first planar segment supports the groove bottom wall, achieving an effect of engaging the two through surface contact rather than line or point contact, thereby increasing the contact area between the connecting segment and the groove bottom wall and improving the stability of the contact and supporting engagement, which is advantageous in more effectively alleviating the problem of deformation of the pressure relief valve plate due to welding tensile stress when welding along the circumferential direction of the pressure relief valve plate. Furthermore, during welding, welding heat can be more effectively dissipated from the groove bottom wall, which is advantageous in more effectively reducing the problem of deformation of the pressure relief valve plate due to welding thermal stress. Furthermore, vibrations received during the operation of the pressure relief valve plate can be more effectively transmitted to the groove bottom wall, thereby alleviating the problem of damage to the pressure relief valve plate due to vibrations.

[0011] In some embodiments, the first planar segment is an annular planar surface that surrounds the entire circumference of the body portion.

[0012] In the above technical aspect, by providing the first planar segment as a continuous, all-around shape, the mounting portion can be supported relatively stably on the groove bottom wall at any position in the entire circumferential direction, which is advantageous in better protecting the pressure release valve plate by further increasing the area of ​​surface contact and engagement between the mounting portion and the groove bottom wall, improving the stability of the support engagement, improving heat transfer efficiency, and improving the vibration transmission range.

[0013] In some embodiments, a surface of the connecting segment facing away from the groove bottom wall includes a second planar segment, and at least a portion of a projection of the second planar segment on the first planar segment along the axial direction of the opening lies within the first planar segment.

[0014] In the above technical aspect, the connecting segment can be easily processed and shaped, and therefore the connecting segment has a relatively uniform wall thickness, a stable shape, and relatively good stability in force application. Furthermore, by obtaining a first planar segment with a larger area, the stability of the contact and supporting engagement between the mounting portion and the groove bottom wall can be further improved, which is advantageous for further increasing the contact area between the mounting portion and the groove bottom wall for heat transfer and vibration transmission.

[0015] In some embodiments, the radial width W1 of the second planar segment is smaller than the radial width W2 of the first planar segment, and / or the radial width W2 of the first planar segment is 0.5 to 8 times the wall thickness T1 of the main body portion, and the radial width W1 of the second planar segment is 0.1 to 5 times the wall thickness T1 of the main body portion.

[0016] In the above technical aspect, the radial width of the first planar segment can be relatively easily increased, which is advantageous for increasing the contact area between the first planar segment and the groove bottom wall, further improving the stability of the contact and supporting engagement between the mounting portion and the groove bottom wall, and further increasing the contact area between the mounting portion and the groove bottom wall for heat transfer and vibration transfer.

[0017] In some embodiments, the wall thickness T3 of the connecting segment is 0.75 to 1.2 times the wall thickness T1 of the main body portion, and / or the axial depth H2 of the relief groove is 0.5 to 3 times the wall thickness T1 of the main body portion.

[0018] In the above technical aspect, by setting T3 to be equal to or greater than 0.75T1 and equal to or less than 1.2T1, the thickness of the connection segment is not too thin, which improves the reliability of support and contact with the groove bottom wall, while not being too thick, which is advantageous for leaving a relatively sufficient depth for the relief groove so that the relief groove can effectively perform the function of relieving tensile stress. By setting H2 to be equal to or greater than 0.5T1 and equal to or less than 3T1, the relief groove depth provides good processability and the processed relief groove has a relatively stable and reliable shape. Furthermore, by setting the relief groove depth to be not too shallow, which allows the relief groove to effectively perform the function of relieving tensile stress, while not being too deep, which is advantageous for leaving a relatively sufficient thickness for the connection segment, which improves the reliability of support and contact between the connection segment and the groove bottom wall.

[0019] In some embodiments, the projection of the opening of the weakened region on the attachment portion along the radial direction lies within the undercut groove.

[0020] In the above technical aspect, when the welding stress of the welded segment and the groove side wall is transmitted toward the weak area along the radial direction of the opening, the relief groove can release the welding stress transmitted toward the weak area, thereby more effectively improving the adverse effects of the welding stress on the weak area.

[0021] In some embodiments, the projection of the mounting portion along the radial direction of the opening in the body portion is entirely within the undercut groove.

[0022] In the above technical aspect, when the welding stress of the welded segment and the groove side wall is transmitted toward the weak area along the radial direction of the opening, the welding stress transmitted toward the weak area by the relief groove can be more fully released, and thus the adverse effects of the welding stress on the weak area can be more effectively improved.

[0023] In some embodiments, the connecting segment and at least one of the cantilever segment and the welding segment are connected by a chamfer.

[0024] The above technical aspect solves the problem of stress concentration due to the transition of a large bending angle at the corresponding connection point, and improves the structural reliability of the pressure relief valve plate, making it less likely to break when the pressure relief valve plate is welded or subjected to force during operation.

[0025] In some embodiments, the end of the cantilever segment remote from the connecting segment is bent over and connected to an edge of the body portion, causing the cantilever segment to tilt relative to the body portion.

[0026] In the above technical aspect, the cantilever segment and the main body are not indirectly connected but are directly connected, and further, by providing that the cantilever segment extends obliquely relative to the main body along the direction from the main body to the connection portion, the cantilever segment can be cantilevered over the opening and / or countersunk groove.In this way, the main body consists only of the cantilever segment, the connection segment, and the welded segment, which has a simple structure, occupies a small space, and is easy to process.

[0027] In some embodiments, the axial step H1 between the thickness side surface of the main body near the groove bottom wall and the thickness side surface of the connecting segment near the groove bottom wall is 0.5 to 2 times the wall thickness T1 of the main body.

[0028] In the above technical aspect, by setting H1 to be equal to or greater than 0.5T1 and equal to or less than 2T1, the extension distance of the cantilever segment in the axial direction of the opening is not too short, which makes it easy to release welding stress at the opening position and depth of the relief groove, and the connection segment has a certain thickness so that it can reliably contact and support the groove bottom wall.On the other hand, by not extending the cantilever segment in the axial direction of the opening in the axial direction of the opening in the axial direction of the opening in the axial direction of the pressure release valve plate, it is advantageous to reduce the space occupied by the pressure release valve plate in the opening axial direction, improve the structural compactness of the battery cell, and improve the energy density per unit volume of the battery cell.

[0029] In some embodiments, the wall thickness T4 of the cantilevered segment is greater than or equal to the wall thickness T1 of the main body portion.

[0030] In the above technical aspect, by setting the wall thickness T4 of the cantilever segment to be equal to or greater than the wall thickness T1 of the main body, the cantilever segment has a relatively large wall thickness, which can more effectively balance the overall force acting on the pressure relief valve plate during the welding and operation process and better exert the functions of releasing stress and absorbing vibration, thereby better protecting the weak areas from the effects of welding stress and improving the stability and reliability of the operation of the pressure relief valve plate.

[0031] In some embodiments, the wall thickness T4 of the cantilever segment is 1.1 to 1.8 times the wall thickness T1 of the main body portion.

[0032] In the above technical aspect, by setting T4 to be greater than or equal to 1.1T1 and less than or equal to 1.8T1, the difference in thickness between the cantilever segments and the main body is not too large, thereby improving the processability of the pressure relief valve plate. Meanwhile, the requirement that the thickness of the cantilever segments be greater than that of the main body can be satisfied, so that the cantilever segments can effectively balance the force acting on the entire pressure relief valve plate during the welding and operation process, and effectively exert the functions of releasing stress and absorbing vibration, thereby better protecting the weak areas from the effects of welding stress and improving the stability and reliability of the operation of the pressure relief valve plate.

[0033] In some embodiments, the body and cantilevered segments are connected by a chamfer.

[0034] The above technical aspect solves the problem of stress concentration due to the large bending angle transition at the connection point between the main body and the cantilever segment, improves the reliability of stress or vibration absorption by the cantilever segment, allows the cantilever segment to relatively effectively perform the functions of stress release and vibration buffering, and improves the effect of the cantilever segment in balancing the force acting on the entire pressure relief valve plate during the welding and operation process.

[0035] In some embodiments, at least the end of the weld segment remote from the groove bottom wall is heat-welded as a whole as a weld mark, whereby the weld mark forms a partial groove wall of the relief groove.

[0036] In the above technical aspect, the dimensions of the relief groove are sufficient, and the relief groove is always available to release stress during the welding process, which is advantageous in increasing the effectiveness of micro-deformation of the cantilever segment and the welded segment, and provides a protective effect to reduce stress transmission to the weak area.

[0037] In some embodiments, the wall thickness T2 of the welded segment is 0.75 to 1.5 times the wall thickness T1 of the main body portion.

[0038] In the above technical aspect, when welding the groove side wall of the countersunk groove using the welding segments, setting T2 to be equal to or greater than 0.75T1 and equal to or less than 1.5T1 makes the thickness of the welding segments not too thin and relatively thick enough for thermal welding, resulting in relatively high connection reliability after welding. On the other hand, the thickness of the welding segments is not too thick, so that the molten pool formed during welding of the welding segments spreads into the relief groove, improving the fluidity of the molten pool, improving weld quality, releasing welding stress, and reducing the adverse effects of welding stress on the brittle region.

[0039] In some embodiments, the wall surface of the weld segment facing the groove side wall in the thickness direction is a weld side wall, and the weld side wall includes a weld wall segment and a guide wall segment, the guide wall segment is connected to the side of the weld wall segment closer to the groove bottom wall, and the guide wall segment extends at an angle toward the groove bottom wall in a direction gradually approaching the main body portion relative to the weld wall segment.

[0040] In the above technical aspect, when the mounting portion is mounted in the counterbore groove, the guide wall segment has a structure that narrows inward relative to the welded wall segment, which acts as a guide, improving the mounting efficiency of the pressure release valve plate and the mounting fixture and allowing for smooth mounting. On the other hand, the welded wall segment has a structure that expands outward relative to the guide wall segment, which utilizes stable engagement between the welded wall segment and the groove side wall of the counterbore groove, improving the yield of welding of both.

[0041] In some embodiments, the axial height H4 of the weld side wall is 1 to 5 times the wall thickness T1 of the main body portion, and / or the axial height H3 of the weld wall segment is 0.5 to 3 times the wall thickness T1 of the main body portion.

[0042] In the above technical aspect, by setting H4 to be equal to or greater than T1 and equal to or less than 5T1, when the weld side wall and the groove side wall of the countersunk groove are welded, the axial height of the weld side wall is not too short and can have a relatively sufficient length to provide the weld wall segment and the guide wall segment, which is advantageous for optimizing the welding effect of the weld wall segment and the guiding effect of the guide wall segment. On the other hand, since the axial height of the weld side wall is not too long, the depth of the countersunk groove engaged with the weld side wall can be reduced, which is advantageous for reducing the thickness of the fixture, and is advantageous for lightweight design and reducing the space occupied by the fixture. By setting H3 to be greater than or equal to 0.5T1 and less than or equal to 3T1, when welding the welded wall segment to the groove side wall of the countersunk groove, the axial height of the welded wall segment is not too short and can have a relatively sufficient length for thermal welding, resulting in relatively high connection reliability after welding. On the other hand, since the axial height of the welded wall segment is not too long, the depth of the countersunk groove welded to the welded wall segment can be reduced, which is advantageous for reducing the thickness of the fixture, favoring a lightweight design, and favoring a reduction in the space occupied by the fixture.

[0043] In some embodiments, the radial width W3 of the guide wall segment in the orthogonal projection along the axial direction of the opening is 0.1 to 0.5 times the wall thickness T1 of the main body portion.

[0044] In the above technical aspect, by setting W3 to be greater than or equal to 0.1T1 and less than or equal to 0.5T1, the radial width of the guide wall segment is not too small, and a relatively effective guiding effect can be achieved. Meanwhile, when the radial widths of the mounting portion and the cantilever segment are constant, the radial width of the guide wall segment is not too large, and space is left to allow the radial width of the connecting segment to be increased, thereby improving the stability of the contact support between the connecting segment and the groove bottom wall and improving the positioning effect and welding quality when the pressure relief valve plate is attached to the mounting fixture.

[0045] In some embodiments, the weakened area is a lightening groove, and the opening direction of the lightening groove and the opening direction of the relief groove are the same or opposite.

[0046] In the above technical aspect, the opening direction of the lightening groove and the opening direction of the relief groove may be the same or opposite, which allows for flexible processing of the pressure release valve plate, and further meets the needs of different application scenarios, thereby diversifying the scenarios that the pressure release valve plate can be used in.

[0047] In some embodiments, the contour line of the lightening groove is an open annular shape that is the same as and concentric with the contour shape of the pressure release valve plate, and the distance between the center of the lightening groove and the mounting portion is greater than the distance between the edge of the lightening groove and the mounting portion.

[0048] In the above technical aspect, the die line of the lightening groove is simple, it is easy to process, and furthermore, it is possible to more reliably realize the opening of the valve.

[0049] In some embodiments, the fixture has a first side and a second side in a thickness direction, and the countersunk groove is formed in an end wall of the fixture on the first side and the groove opening toward the first side, or the countersunk groove is formed in an end wall of the fixture on the second side and the groove opening toward the second side.

[0050] In the above technical aspect, the pressure relief valve plate is not limited to being attached to the inside or outside of the fixture, which allows for flexible installation of the pressure relief valve plate, meets the installation needs of different types of fixtures, and diversifies the situations in which the pressure relief valve plate can be used. When the pressure relief valve plate is attached to the side of the fixture away from the accommodating chamber, it is possible to more effectively prevent conductive metals such as slag from falling into the accommodating chamber, thereby improving the reliability of the battery cell.

[0051] In some embodiments, the pressure relief valve plate has a mounting portion and a main body portion formed by press molding, and the main body portion has a constant thickness flat plate structure.

[0052] In the above technical aspect, the manufacturing process of the pressure release valve plate is simple, and it is easy to ensure that the thickness at each position of the mounting part meets the design requirements. Furthermore, because the bent shape of the mounting part can protect the weak area, the main body does not need to be specially processed to protect the weak area, and a simple flat plate structure of uniform thickness is sufficient, which is advantageous in simplifying the structure and processing of the main body.

[0053] In a second aspect, embodiments of the present application further provide a battery cell including a housing and an electrode assembly, the electrode assembly being disposed within the housing, the housing including the pressure release member described above.

[0054] In the above technical aspect, the reliability and stability of the operation of the pressure release member of the embodiment of the present application is improved, which is advantageous in improving the reliability and stability of the operation of the battery cell.

[0055] In some embodiments, the housing includes a body and a cover, the cover adapted to cover the body in an open position, and one of the body and the cover forming a fixture.

[0056] In the above technical aspect, the pressure release valve plate can be attached to either the body or the cover, allowing for flexible selection of the attachment position of the pressure release valve plate, thereby improving flexibility in battery cell design.

[0057] In a third aspect, embodiments of the present application further provide a battery comprising the battery cell described above.

[0058] The above technical aspect is advantageous in improving the reliability and stability of the operation of the battery cell of the embodiment of the present application, thereby improving the reliability and stability of the operation of the battery.

[0059] In a fourth aspect, embodiments of the present application further provide an electrical device comprising the battery described above.

[0060] In the above technical aspect, the reliability and stability of the operation of the battery according to the embodiment of the present application are improved, which is advantageous in improving the reliability and stability of the operation of electrical devices. [Brief explanation of the drawings]

[0061] In order to more clearly explain the technical aspects of the embodiments of the present application, the drawings necessary for the embodiments are briefly described below. It should be understood that the following drawings only show some embodiments of the present application, and should not be considered as limiting the scope, and those skilled in the art can obtain other related drawings based on these drawings without paying creative labor.

[0062] [Figure 1] 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] FIG. 1 is an exploded view of a battery according to some embodiments of the present application. [Figure 3] 1 is a structural schematic diagram of a battery cell according to some embodiments of the present application; [Figure 4] 1 is a cross-sectional view of a pressure release member of a battery cell according to some embodiments of the present application. [Figure 5]FIG. 5 is a structural schematic diagram of the pressure release valve plate shown in FIG. 4. [Figure 6] FIG. 6 is a partial enlarged view of the pressure release valve plate shown in FIG. 5. [Figure 7] FIG. 7 is a parameter identification diagram of a partial structure of the pressure release valve plate shown in FIG. 6. [Figure 8] 1 is a cross-sectional view of an application of a pressure relief member according to some embodiments of the present application. [Figure 9] 10A and 10B are cross-sectional views of the application of pressure release members according to some other embodiments of the present application. [Figure 10] 10A and 10B are cross-sectional views of the application of a pressure release member according to some embodiments of the present application. [Figure 11] 10A to 10C are cross-sectional views of applications of pressure relief members according to further embodiments of the present application. [Figure 12] 10A to 10C are structural schematic diagrams of pressure release valve plates according to some other embodiments of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0063] In order to clarify the objectives, technical aspects and advantages of the embodiments of the present application, the technical aspects of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, but it is clear that the described embodiments are only some of the embodiments of the present application and do not represent all of the embodiments. All other embodiments that a person skilled in the art can obtain based on the embodiments of the present application without paying creative labor fall within the scope of protection of the present application.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. In this application, the terms used in the specification of the application are merely for the purpose of describing specific embodiments and are not intended to limit the application. The terms "comprise" and "have" and any variations thereof in the specification, claims, and description of the drawings of this application are intended to cover a non-exclusive "inclusion." The terms "first," "second," etc. in the specification, claims, or drawings of this application are intended to distinguish different objects and are not intended to describe a specific order or a subordinate relationship.

[0065] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described with reference to the embodiment can be included in at least one embodiment of the present application. The appearances of the term in various places in the specification do not necessarily refer to the same embodiment, nor are they exclusive, independent, or alternative embodiments of other embodiments.

[0066] In the description of this application, unless otherwise clearly specified and limited, the terms "attach," "connect," "connect," and "attach" should be understood in a broad sense. For example, they may be fixedly connected, detachably connected, or integrally connected, or may be directly connected, indirectly connected via an intermediate medium, or may be internally connected between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0067] The term "and / or" in this application is merely used to explain the relationship between related objects, and indicates that three types of relationships can exist. For example, A and / or B can indicate three situations: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after it are in an "or" relationship.

[0068] In several embodiments of the present application, the same reference numerals indicate the same elements, and for the sake of brevity, detailed descriptions of the same elements in different embodiments will be omitted. It should be understood that the thickness, length, width, etc. of various elements in the embodiments of the present application shown in the drawings, and the overall thickness, length, width, etc. of the integrated device, are merely illustrative and do not limit the present application in any way.

[0069] As used herein, the term "plurality" means two or more (including two).

[0070] In this application, the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries, magnesium ion batteries, etc., but are not limited to these in the embodiments of this application. The battery cells may be cylindrical, flat, rectangular, or have other shapes, but are not limited to these in the embodiments of this application. Battery cells are generally packaged in three types: prismatic battery cells, rectangular battery cells, and soft-pack battery cells, but are not limited to these in the embodiments of this application.

[0071] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery module typically includes multiple battery cells. A battery pack typically includes a case for packaging one or more battery cells or one or more battery modules. The case can prevent liquids and other foreign objects from affecting the charging and discharging of the battery cells.

[0072] A battery cell typically includes an electrode assembly, an electrolyte, and a housing. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell operates primarily through the movement of metal ions between the positive and negative electrode sheets.

[0073] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer being directly or indirectly applied to the positive electrode current collector, the positive electrode current collector not coated with the positive electrode active material layer being projected onto the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector not coated with the positive electrode active material layer being a positive electrode tab. For example, in a lithium-ion battery, the material of the positive electrode current collector may be aluminum, and the material of the positive electrode active material layer may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc.

[0074] The negative electrode sheet generally includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being directly or indirectly applied to the negative electrode current collector, the negative electrode current collector not coated with the negative electrode active material layer being protruding from the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector not coated with the negative electrode active material layer being a negative electrode tab. The material of the negative electrode current collector may be copper, and the material of the negative electrode active material layer may be carbon, silicon, or the like.

[0075] In order to ensure that a large current can flow without fusing, the positive electrode tabs are multiple and stacked, and the negative electrode tabs are multiple and stacked. The electrode assembly may have a wound structure or a stacked structure, and the embodiments of the present application are not limited thereto.

[0076] The material of the separator is not limited, but may be, for example, polypropylene or polyethylene.

[0077] The housing typically includes a body and a cover, and the body and cover may be separate components, or the body may have an opening, and the cover is closed over the opening to form an internal environment of the battery cell, containing the electrode assembly, electrolyte, etc. The body may be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the cover may also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., but the present application is not limited thereto.

[0078] The body may have various shapes and dimensions, such as a rectangular parallelepiped, a cylindrical shape, or a hexagonal prism. The shape of the body can be determined according to the specific shape and dimensions of the electrode assembly. The cover closes the opening of the body, isolating the internal environment of the battery cell from the external environment. The shape of the cover can be tailored to fit the body. For example, the cover may be made of a material with a certain hardness and strength, which makes it less likely to deform when subjected to pressure or impact. This allows the battery cell to have good structural strength and improved reliability. The cover may be provided with functional members such as electrode terminals, which may be used to electrically connect to the electrode assembly to output or input electrical energy from the battery cell.

[0079] In recent years, new energy vehicles have evolved dramatically, and in the field of electric vehicles, batteries play an irreplaceable and important role as the power source of electric vehicles. As a core component of new energy vehicles, batteries are subject to high reliability requirements. However, if a thermal runaway or internal short circuit occurs during battery operation, a large amount of heat and gas is generated in a short period of time. This can affect battery reliability if it reaches a certain level. Therefore, in order to improve battery reliability, a pressure relief mechanism is usually provided on the housing body or cover to relieve the smoke and pressure generated during thermal runaway or short circuit of the battery, or to relieve the internal pressure or temperature of the battery cell when it reaches a threshold.

[0080] The threshold design may vary depending on design needs, for example, the threshold design may be determined by one or more materials of the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell. When the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure release mechanism performs an operation or a fragile structure provided in the pressure release mechanism breaks to form an opening or a passage through which the internal pressure or temperature is released, thereby improving the reliability of the battery cell.

[0081] The pressure relief valve plate is a typical pressure relief mechanism and may be a flat plate structure with a lightening groove, which acts as a fragile structure to reduce the thickness of the pressure relief valve plate in parts, with the depth of the lightening groove being smaller than the thickness of the pressure relief valve plate in other areas other than the lightening groove, thereby achieving the purpose of not penetrating the pressure relief valve plate. Under normal conditions, the pressure relief valve plate and the housing are sealed together, sealing off the internal environment formed within the housing and making it impermeable to air. When the internal pressure or temperature of the battery cell reaches a threshold, gas in the internal environment expands and the air pressure within the housing increases to exceed the threshold. The pressure relief valve plate then ruptures at the lightening groove, thereby communicating between the inside and outside of the housing and allowing the gas within the housing to be vented through the ruptured portion of the pressure relief valve plate, improving the reliability of the battery cell.

[0082]

[0003] In general, the pressure relief valve plate and the housing, such as the body or cover, are processed separately, and the pressure relief valve plate is formed by pressing or other methods and then connected to the housing using a welding process such as laser welding. During the welding process between the pressure relief valve plate and the housing, the metal material is partially heated and melted to form a molten pool, which is then cooled and crystallized. When the metal material is partially heated and cooled, welding tensile stress is generated inside the welded joint, and this tensile stress is transferred to the lightening groove area of ​​the pressure relief valve plate. If the heat input is too large or welding is repeated, the welding tensile stress will be too large, which will thin the lightening groove area of ​​the pressure relief valve plate and reduce the pressure resistance of the pressure relief valve plate, causing the battery to open early during operation.

[0083] Based on the above considerations, in order to solve the problem of the battery valve opening prematurely during operation, the present application proposes a pressure release member, which includes a mounting fixture and a pressure release valve plate, the mounting fixture may be part of a housing such as a body or a cover, the mounting fixture has an opening, the mounting fixture has a countersunk groove formed circumferentially around the opening, the countersunk groove includes a groove bottom wall and a groove side wall, the pressure release valve plate is configured to cover the opening, and the pressure release valve plate includes a main body portion and a mounting portion, the main body portion has a weakened area, and the mounting portion is connected to the outer periphery of the main body portion and is bent so as to be supported by the groove bottom wall and welded to the groove side wall.

[0084] As a result, by providing the mounting portion located in the outer peripheral region of the pressure release valve plate and welded to the groove side wall in a bent shape, stress is reduced at the bent mounting portion in the region close to the welding position of the main body portion which has a weak region, the welding tensile stress transmitted to the weak region in the main body portion is reduced, and the adverse effect of the welding tensile stress on the weak region in the main body portion is reduced, thereby improving the problem of the weak region opening first during the operating process of the pressure release valve plate. Furthermore, because the bent mounting portion is supported by the bottom wall of the groove, heat generated by welding can be dissipated through the bottom wall of the groove, thereby solving the problem of deformation of the pressure release valve plate due to welding heat. Furthermore, when welding is performed in the circumferential direction of the pressure release valve plate, i.e., along the contour extension direction of the pressure release valve plate, the position of the mounting portion to be welded in the circumferential direction can benefit from the supporting effect of the bottom wall of the groove, and is less likely to be deformed in the circumferential direction by tensile force at the position during and after welding. This reduces circumferential deformation of the pressure release valve plate during circumferential welding, solving the problem of warpage deformation occurring in the circumferential welding process of the pressure release valve plate, improving welding quality, and further improving the uniformity of the shape at each position around the entire circumferential direction of the pressure release valve plate. This in turn improves the uniformity of force acting on the pressure release valve plate during its operation, allowing the valve opening timing to meet the design requirements and improving the stability and reliability of the operation of the pressure release valve plate. In addition, since the mounting part is bent and supported by the bottom wall of the groove and welded to the side wall of the groove, the bent structure absorbs vibrations and effectively transmits vibrations to the mounting fixture, thereby eliminating problems such as deformation or breakage of the pressure release valve plate due to vibration, thereby improving the vibration-proofing performance of the pressure release valve plate and increasing the stability and reliability of the pressure release valve plate during its operation.

[0085]

[0013] In other words, in the pressure relief member according to the embodiment of the present application, the mounting part on the outer periphery of the main body is bent, which reduces stress due to the bent structure and improves the adverse effects of welding stress on the weak areas of the pressure relief valve plate during the welding process between the pressure relief valve plate and the mounting fixture, thereby alleviating the problem of premature opening and increasing the accuracy of the valve opening timing during the operation of the pressure relief valve plate. It is also advantageous to improve the vibration-proof performance of the pressure relief valve plate and improve the stability and reliability of the operation of the pressure relief valve plate. Meanwhile, by supporting the mounting part on the groove bottom wall and welding it to the groove side wall, the mounting part is supported by the groove bottom wall and can improve the deformation problem during the welding process between the pressure relief valve plate and the mounting fixture, thereby reducing the occurrence of problems such as warpage deformation of the mounting part weld and improving the welding quality, thereby further improving the stability and reliability of the pressure relief valve plate during the operation of the pressure relief valve plate.

[0086] The batteries disclosed in the embodiments of the present application may be used in electrical devices such as, but not limited to, vehicles, watercraft, or aircraft.

[0087] An embodiment of the present application provides an electric device that uses a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a boat, a spacecraft, etc. Among these, the electric toy may include a stationary or mobile electric toy such as a game console, an electric car toy, an electric boat toy, an electric aircraft toy, etc., and the aerospace vehicle may include an aircraft, a rocket, a space shuttle, a spaceship, etc.

[0088] In the following embodiment, for convenience of explanation, an electric device according to an embodiment of the present invention is a vehicle.

[0089] Please refer to FIG. 1. FIG. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 may be an internal combustion engine vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range-extended vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head, or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, as the operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, and the controller 200 is used to control the power supply of the battery 100 to the motor 300, for example, for starting the vehicle 1000, navigation, and operating power consumption needs during driving.

[0090] In some embodiments of the present application, the battery 100 is not only used as the operating power source for the vehicle 1000, but also as the power source for driving the vehicle 1000, and can provide driving power for the vehicle 1000 as an alternative or partial alternative to gasoline or natural gas.

[0091] Please refer to Figure 2. Figure 2 is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a case 10 and a plurality of battery cells 20, which are housed within the case 10. The case 10 provides an installation space for the battery cells 20, and the case 10 may have a variety of structures. In some embodiments, the case 10 may include a first case body 101 and a second case body 102, which are closed to each other, and the first case body 101, together with the second case body 102, define an installation space for housing the battery cells 20. The second case body 102 may have a hollow structure with one end open, and the first case body 101 may have a plate-like structure, and the first case body 101 may be covered with the open side of the second case body 102, thereby defining an installation space together with the second case body 102. The first case body 101 and the second case body 102 may both have a hollow structure with one end open, and the open side of the first case body 101 may be covered with the open side of the second case body 102. Of course, the case 10 formed by the first case body 101 and the second case body 102 may have a variety of shapes, such as a cylindrical body or a rectangular parallelepiped.

[0092] In the battery 100, the plurality of battery cells 20 may be connected in series, in parallel, or in multiple rows; multiple row connection refers to not only a series connection among the plurality of battery cells 20 but also a parallel connection among the plurality of battery cells 20. The plurality of battery cells 20 may be directly connected in series, in parallel, or in multiple rows, and then the entire battery cell configuration may be housed in the case 10. Of course, the battery 100 may be configured such that the plurality of battery cells 20 are connected in series, in parallel, or in multiple rows to form a battery module, and then the plurality of battery modules are connected in series, in parallel, or in multiple rows to form a whole battery module housed in the case 10. The battery 100 may further include other structures, such as a thermal management system for regulating the temperature of the battery cells 20 and bus members for electrically connecting the plurality of battery cells 20 together.

[0093] Please refer to FIG. 3. FIG. 3 is a structural schematic diagram of a battery cell 20 according to some embodiments of the present application. The battery cell 20 may be a secondary battery or a primary battery, and may be, but is not limited to, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery. For example, in FIG. 3, the housing 1 of the battery cell 20 has a rectangular parallelepiped shape and includes a body 11 and a cover 12. The body 11 is open at one end or at both ends and is covered by the cover 12 in the open position. The cover 12 is provided with a pressure relief valve plate 2 for releasing the internal pressure or temperature of the housing 1 when the internal pressure or temperature of the battery cell 20 reaches a threshold value. However, this is not limited thereto. For example, in other embodiments of the present application, the pressure relief valve plate 2 may be provided on the body 11. Furthermore, the shape of the housing 1 of the battery cell 20 is not limited thereto. For example, it may be a cylindrical body, a rectangular prism body, a flat body, or the like.

[0094] Please refer to Figures 4 and 5. Figure 4 is a partial cross-sectional view of a pressure release member 201 according to some embodiments of the present application, and Figure 5 is a structural schematic diagram of the pressure release valve plate 2 shown in Figure 4. According to some embodiments of the present application, the pressure release member 201 includes a mounting fixture 3 and a pressure release valve plate 2. The configuration of the mounting fixture 3 is not limited; please refer to Figures 3 and 4 again. The mounting fixture 3 may be part of the housing 1 of the battery cell 20. For example, if the housing 1 is composed of a body 11 and a cover 12, the mounting fixture 3 may be the body 11 or the cover 12. Furthermore, for example, if the housing 1 is an aluminum laminate film for a soft pack (an example of this is not shown), the mounting fixture 3 may be an aluminum laminate film.

[0095] Please refer to Figure 4 again. The fixture 3 has an opening 31, and the fixture 3 has a countersunk groove 32 that surrounds the circumferential direction of the opening 31, the countersunk groove 32 including a groove bottom wall 321 and a groove side wall 322. Note that the "circumferential direction of the opening 31" refers to the direction in which the contour of the opening 31 extends. Since the countersunk groove 32 extends along the entire periphery of the contour of the opening 31, the countersunk groove 32 forms an annular shape that surrounds the opening 31, and the opening 31 is located in the inner annular region of the countersunk groove 32. Of these, the shape of the countersunk groove 32 matches the shape of the opening 31. For example, if the opening 31 is circular, the countersunk groove 32 will be a circular ring surrounding the circle. Also, for example, if the opening 31 is elliptical, the countersunk groove 32 will be an elliptical ring surrounding the ellipse. Furthermore, for example, if the opening 31 is track-shaped, also known as an oval, the countersunk groove 32 will be a track ring surrounding the track shape. Furthermore, for example, if the opening 31 is rectangular, the countersunk groove 32 will be a rectangular ring surrounding the rectangle.

[0096] The countersunk groove 32 is recessed along the axial direction of the opening 31, and the "axial direction of the opening 31" is the penetration direction of the opening 31, for example, the first direction X shown in FIG. 4 . One end of the countersunk groove 32 in the first direction X is opened as a groove mouth 323 of the countersunk groove, and the other end of the countersunk groove 32 in the first direction X forms a groove bottom wall 321. The inner end of the countersunk groove 32 in the radial direction of the opening 31, i.e., one end close to the center of the opening 31, is open, and the outer end of the countersunk groove 32 in the radial direction of the opening 31, i.e., one end far from the center of the opening 31, forms a groove side wall 322. Of these, the "radial direction of the opening 31" is the direction of a line connecting the center of the opening 31 and any one point on the outline of the opening 31. Since there are an infinite number of points on the outline, there are an infinite number of radial directions of the opening 31. For example, in the cross section shown in FIG. 4 , the radial direction of the opening 31 is the second direction Y.

[0097] 4 and 5 again, the pressure release valve plate 2 is provided to cover the opening 31, and includes a main body 21 and an attachment portion 22, with the main body 21 having a weakened region 211. The specific form of the weakened region 211 is not limited, and for example, a lightening groove 23 may be provided in a partial region of the main body 21, and the main body 21 may be weaker at the region of the lightening groove 23 than at other regions. Also, for example, the strength of the material at a partial region of the main body 21 is weaker than the strength of the material at other regions of the main body 21, so that the region where the material is relatively weak is relatively weak. Any of these relatively weak regions may be defined as the weakened region 211.

[0098] 4 and 5 again, the mounting portion 22 is connected to the outer periphery of the main body 21, and is bent so as to be supported on the groove bottom wall 321 and welded to the groove side wall 322. The mounting portion 22 is connected to the main body 21 at a position far from the center of the pressure release valve plate 2, and when the pressure release valve plate 2 is provided to cover the opening 31, the mounting portion 22 located on the outer periphery of the main body 21 can engage with the countersunk groove 32 on the outer periphery of the opening 31, and the weakened region 211 in the main body 21 located on the inner periphery of the mounting portion 22 corresponds to the opening 31.

[0099] 3 and 4, when pressure inside the housing 1 of the battery cell 20 increases, it can be transmitted to the weakened area 211 through the opening 31, causing the weakened area 211 to burst and release the pressure. Illustratively, an orthogonal projection is generated along the axial direction of the opening 31, for example, the first direction X shown in FIG. 4, and the orthogonal projection of the main body 21 is completely or almost completely within the orthogonal projection range of the opening 31, thereby improving the reliability of pressure release from the weakened area 211.

[0100] In some embodiments of the present application, at least a portion of the attachment portion 22 is not flat but is bent, but the specific bending position and bending shape are not limited and may be, for example, be bent once or multiple times, and are not limited to the shape shown in Fig. 5. Furthermore, the end of the attachment portion 22 that connects to the main body portion 21 may be bent or flat, i.e., the attachment portion 22 may be bent directly from the edge of the main body portion 21 in a direction away from the main body portion 21, at an angle relative to the main body portion 21, or the attachment portion 22 may first extend partially along the extension direction of the main body portion 21 from the edge of the main body portion 21 in a direction away from the main body portion 21, and then bent at an angle relative to the extension direction of the main body portion 21, and are not limited thereto.

[0101] In the above technical form of the present application, the mounting portion 22 located in the outer peripheral region of the pressure release valve plate 2 and welded to the groove side wall 322 is provided in a bent form, thereby reducing the welding tensile stress transmitted to the weak region 211 of the main body portion 21 by the bent mounting portion 22 in the region close to the welding position of the main body portion 21 having the weak region 211, thereby reducing the adverse effect of the welding tensile stress on the weak region 211 of the main body portion 21, and improving the problem of the weak region 211 opening first during the operation process of the pressure release valve plate 2.

[0102]

[0013] Furthermore, because the bent mounting portion 22 is supported by the groove bottom wall 321 and welded to the groove side wall 322, heat generated by welding can be dissipated through the groove bottom wall 321, thereby eliminating the problem of deformation of the pressure relief valve plate 2 due to welding heat. Furthermore, when welding is performed in the circumferential direction of the pressure relief valve plate 2, i.e., along the contour extension direction of the pressure relief valve plate 2, the circumferential welded position of the mounting portion 22 can benefit from the supporting function of the groove bottom wall 321, and is less likely to deform due to tensile force at the circumferential position during and after welding. This reduces circumferential deformation of the pressure relief valve plate 2 during circumferential welding, and solves the problem of warpage deformation occurring during circumferential welding of the pressure relief valve plate 2, improving welding quality, and further improving the uniformity of the shape at each position around the entire circumferential direction of the pressure relief valve plate 2. This in turn improves the uniformity of force acting on the pressure relief valve plate 2 during its operation, ensuring that the valve opening timing meets the design requirements, thereby improving the stability and reliability of the operation of the pressure relief valve plate 2.

[0103] In addition, since the mounting part 22 is bent and supported by the groove bottom wall 321 and welded to the groove side wall 322, the bent structure absorbs vibrations and effectively transmits vibrations to the mounting fixture 3, thereby improving problems such as deformation or breakage of the pressure release valve plate 2 due to vibration, thereby improving the vibration-proofing performance of the pressure release valve plate 2 and increasing the stability and reliability of the pressure release valve plate 2 during its operation.

[0104] In other words, the pressure release member 201 according to the embodiment of the present application is advantageous in improving the adverse effect of welding stress on the weak area 211 of the pressure release valve plate 2 during the welding process between the pressure release valve plate 2 and the mounting fixture 3, thereby alleviating the problem of the valve opening prematurely, and in improving problems such as warpage deformation during welding, improving welding quality, and increasing the accuracy of the valve opening timing during the operation process of the pressure release valve plate 2. Furthermore, it is advantageous in improving the vibration-proof performance of the pressure release valve plate 2, and improving the stability and reliability of the pressure release valve plate 2 during the operation process.

[0105]

[0023] As a result, in the pressure release member 201 according to the embodiment of the present application, the mounting part 22 on the outer periphery of the main body 21 is bent, which reduces stress due to the bent structure and improves the adverse effect of welding stress on the weak area 211 of the pressure release valve plate 2 during the welding process between the pressure release valve plate 2 and the mounting fixture 3, thereby eliminating the problem of the valve opening prematurely and increasing the accuracy of the valve opening timing during the operation of the pressure release valve plate 2. This is advantageous to improve the vibration-proof performance of the pressure release valve plate 2 and improve the stability and reliability of the operation of the pressure release valve plate 2. Meanwhile, the mounting part 22 is supported by the groove bottom wall 321 and welded to the groove side walls 322, which improves the problem of deformation of the pressure release valve plate 2 due to the support of the mounting part 22 by the groove bottom wall 321 during the welding process between the pressure release valve plate 2 and the mounting fixture 3. This reduces the occurrence of problems such as warpage deformation during welding of the mounting part 22 and improves the welding quality, thereby further improving the stability and reliability of the operation of the pressure release valve plate 2.

[0106] 4 and 5 again, according to some embodiments of the present application, the attachment portion 22 includes a cantilever segment 221, a connection segment 222, and a welded segment 223, which are sequentially connected from the inside to the outside in the radial direction of the opening 31, the connection segment 222 is supported by the groove bottom wall 321, the cantilevered segment 221 is cantilevered above the opening 31 and / or the countersunk groove 32, and both the cantilevered segment 221 and the welded segment 223 are bent relative to the connection segment 222 toward the groove opening 323 of the countersunk groove, thereby forming a relief groove 224 between the cantilevered segment 221, the connection segment 222, and the welded segment 223, and the welded segment 223 is welded to the groove side wall 322.

[0107] Note that the term "bending" in this application does not limit the process, but merely represents a form. The phrase "both the cantilever segment 221 and the welded segment 223 are bent relative to the connecting segment 222 toward the opening 323 of the countersunk groove" does not mean that the cantilever segment 221 itself is bent, nor that the welded segment 223 itself is bent, but rather that the cantilever segment 221 and the welded segment 223 extend relative to the connecting segment 222 toward the opening 323 of the countersunk groove, thereby forming the mounting portion 22 in a bent form. Of course, in other embodiments of this application, at least one of the cantilever segment 221 and the welded segment 223 may be bent as needed.

[0108] Among these, "the cantilever segment 221 is cantilevered on the opening 31 and / or the countersunk groove 32" means that an orthogonal projection is generated along the axial direction of the opening 31, for example, the first direction X shown in FIG. 4, and the orthogonal projection of the cantilever segment 221 is on the opening 31 and / or the countersunk groove 32, and the cantilever segment 221 is in a cantilevered state without contacting either the opening 31 or the countersunk groove 32.

[0109] Among these, the mounting portion 22 is located around the main body 21 and serves to connect the pressure relief valve plate 2 and the mounting fixture 3. The mounting portion 22 includes a bent portion made up of the cantilever segment 221, the connecting segment 222, and the welding segment 223. When the welding segment 223 is welded to the groove side wall 322, the side of the welding segment 223 away from the groove side wall 322 forms a relief groove 224. This allows the welding segment 223 to gradually melt and / or deform, thereby releasing the welding tensile stress and thereby reducing the adverse effects of the welding tensile stress on the weak region 211. Furthermore, because the side of the welding segment 223 away from the relief groove 224 is welded to the groove side wall 322, the welding tensile stress is not directly transmitted to the main body 21 in the radial direction of the opening 31, for example, in the second direction Y shown in FIG. 4 , but is partially transmitted to the relief groove 224 for release, thereby reducing the adverse effects of the welding tensile stress on the weak region 211.

[0110] Furthermore, because the raised cantilever segment 221 is located between the fragile area 211 and the relief groove 224, it balances and absorbs stress and vibration during the welding and operation of the pressure release valve plate 2, thereby reducing the adverse effects of force on the fragile area 211. Furthermore, the cantilever segment 221 balances the distribution of force acting on the entire pressure release valve plate 2 through slight deformation during the operation of the pressure release valve plate 2, making the force acting on the pressure release valve plate 2 more uniform and solving the problem of uneven partial deformation during the operation of the pressure release valve plate 2, thereby improving the fatigue resistance of the pressure release valve plate 2 during its operation and increasing the operational reliability and stability of the pressure release valve plate 2. Furthermore, during long-term operation of the pressure release valve plate 2, the cantilever segment 221 relieves the phenomenon of stress concentration on the pressure release valve plate 2 due to gas or vibration generated inside the battery 100 through slight deformation, thereby improving the long-term operational stability and vibration-proofing ability of the pressure release valve plate 2.

[0111] In addition, since the connecting segment 222 involved in the definition of the relief groove 224 is supported by the groove bottom wall 321, the mounting part 22 can be supported relatively stably by the groove bottom wall 321, which improves the convenience and stability of the mounting part 22 when it is attached to the countersunk groove 32. Meanwhile, it effectively solves the problem of warping deformation of the pressure release valve plate 2 during the circumferential welding of the pressure release valve plate 2, improves the welding quality, and improves the uniformity of the force acting on the pressure release valve plate 2, which is advantageous to improving the stability and reliability of the operation of the pressure release valve plate 2.

[0112] For example, when thermal welding such as laser welding is used, the welded segments 223 are thermally melted and solidified together with the fixture 3 during welding. Because the welded segments 223 are involved in the melting and solidification, thermal stress in the welded segments 223 is effectively relieved, mitigating the adverse effects of welding tensile stress on the weak area 211. After the welded segments 223 melt, the side of the welded segments 223 closest to the main body 21 has a relief groove 224. Because there is no metallic barrier, the molten pool metal spreads toward the relief groove 224 under its own weight, improving the fluidity of the molten pool and improving weld quality. The relief groove 224 may remain after welding. The welding between the pressure relief valve plate 2 and the fixture 3 in the embodiments of the present application is not limited to laser welding, and may be, for example, plasma welding, electron beam welding, brazing welding, or pressure welding.

[0113] As described above, the pressure relief valve plate 2 is provided with the relief groove 224 and the cantilever segment 221, the welding segment 223 on the side of the relief groove 224 farther from the weak area 211 is welded to the groove side wall 322, and the connecting segment 222 on the side facing the groove bottom wall 321 of the relief groove 224 is supported by the groove bottom wall 321. This relieves the welding stress generated during welding between the pressure relief valve plate 2 and the fixture 3 and reduces the welding stress transmitted to the weak area 211, effectively reducing the adverse effects of the welding stress on the weak area 211 and improving the welding quality between the pressure relief valve plate 2 and the fixture 3, thereby improving the stability of the quality after welding and the operational reliability of the pressure relief valve plate 2. Furthermore, the cantilever segment 221 balances the force distribution over the entire pressure relief valve plate 2 through slight deformation during long-term operation of the pressure relief valve plate 2, for example, the cantilever segment 221 relieves the phenomenon of stress concentration on parts of the pressure relief valve plate 2 due to gas or vibration generated inside the battery 100 through slight deformation, making the force applied to the pressure relief valve plate 2 more uniform and solving the problem of uneven partial deformation during operation of the pressure relief valve plate 2, thereby improving the fatigue resistance and vibration isolation capabilities of the pressure relief valve plate 2 during operation, and increasing the operational reliability and stability of the pressure relief valve plate 2. At the same time, the structure of the relief groove 224 increases the ductility of the weld pool and improves weld quality.

[0114] That is, by providing the mounting part 22 in the above structural form, it is possible to effectively alleviate the adverse effects of welding stress on the weak area 211 of the pressure release valve plate 2, improve the distribution of force acting during the operation of the pressure release valve plate 2, make the force acting more uniform, improve the vibration-proofing and fatigue resistance capabilities of the pressure release valve plate 2, and ultimately improve the reliability and stability of the operation of the pressure release valve plate 2. In addition, the structure of the mounting part 22 in the above structural form is simple and easy to process.

[0115] Please refer to Figures 4 and 5 again, and also to Figure 6 in combination. Figure 6 is a partially enlarged view of the pressure relief valve plate 2 shown in Figure 5. In some embodiments of the present application, the surface of the connecting segment 222 facing the groove bottom wall 321 includes a first flat segment 2221, which is arranged parallel or approximately parallel to the groove bottom wall 321, thereby providing surface contact and support engagement between the first flat segment 2221 and the groove bottom wall 321. In this way, the first flat segment 2221 supports the groove bottom wall 321, achieving the effect of engaging the first flat segment 2221 with the groove bottom wall 321 in surface contact rather than line or point contact, thereby increasing the contact area between the connecting segment 222 and the groove bottom wall 321 and improving the stability of the contact and support engagement, which is advantageous for better alleviating the problem of deformation of the pressure relief valve plate 2 due to welding tensile stress when welding along the circumferential direction of the pressure relief valve plate 2. Furthermore, during welding, the welding heat can be dissipated to a greater extent from the groove bottom wall 321, which is advantageous in better reducing the problem of welding thermal stress causing deformation of the pressure release valve plate 2. Furthermore, the vibrations received during the operation of the pressure release valve plate 2 can be transmitted to a greater extent by the groove bottom wall 321, thereby alleviating the problem of the pressure release valve plate 2 being damaged by the vibrations.

[0116] In some embodiments, the first flat segment 2221 is an annular flat surface surrounding the entire circumference of the main body 21. By providing the first flat segment 2221 in a continuously extending, circumferential form, the mounting portion 22 can be supported relatively stably on the groove bottom wall 321 at any position in the entire circumferential direction, and this further increases the surface area of ​​engagement between the mounting portion 22 and the groove bottom wall 321, improving the stability of the support engagement, further increasing the contact area for heat transfer between the mounting portion 22 and the groove bottom wall 321, better alleviating the problem of deformation of the pressure release valve plate 2 due to thermal stress, further increasing the vibration transmitted from the pressure release valve plate 2 to the groove bottom wall 321, and better protecting the pressure release valve plate 2. Of course, the present application is not limited thereto. For example, in other embodiments of the present application, the first flat segment 2221 may be provided discontinuously along the annular circumference, or the first flat segment 2221 may be provided in an open annular structure.

[0117] 4 to 6 again, in some embodiments of the present application, the surface of the connecting segment 222 away from the groove bottom wall 321 includes a second planar segment 2222, and at least a portion of the projection of the second planar segment 2222 onto the first planar segment 2221 along the axial direction of the opening 31 (e.g., the first direction X shown in FIG. 6 ) is within the first planar segment 2221. This makes it easy to process and shape the connecting segment 222, and the connecting segment 222 has a relatively uniform wall thickness, a stable shape, and relatively good stability in force application. Furthermore, by obtaining the first planar segment 2221 with a larger area, the stability of the contact and supporting engagement between the mounting portion 22 and the groove bottom wall 321 is further improved, which is advantageous for further increasing the contact area between the mounting portion 22 and the groove bottom wall 321 for heat transfer and vibration transmission.

[0118] Please refer to Figure 6 again and in combination with Figure 7. Figure 7 is a parameter identification diagram of the partial structure of the pressure relief valve plate 2 shown in Figure 6. In some embodiments of the present application, the radial width W1 of the second planar segment 2222 is smaller than the radial width W2 of the first planar segment 2221. Note that the "radial width" described herein refers to the width in the radial direction of the opening 31, for example, in the second direction Y shown in Figure 6. As described above, since the opening 31 has an infinite number of radial directions, the value of the radial width W1 in each radial direction may be the same or different, and the value of the radial width W2 in each radial direction may be the same or different. However, regardless of the specific values, it is required that the radial width W1 in the same radial direction be smaller than the radial width W2.

[0119] As a result, since the radial width of the first planar segment 2221 is relatively large, it can achieve more effective surface contact with the groove bottom wall 321, which is advantageous in further improving the stability of the contact and supporting engagement between the mounting portion 22 and the groove bottom wall 321 and further increasing the contact area for heat transfer and vibration transmission between the mounting portion 22 and the groove bottom wall 321.

[0120] 6 and 7 again, in some embodiments of the present application, the radial width W2 of the first planar segment 2221 is 0.5 to 8 times, for example, 0.5, 1, 2, 3, 4, 5, 6, 7, 8 times, etc., the thickness T1 of the main body portion 21, and the radial width W1 of the second planar segment 2222 is 0.1 to 5 times, for example, 0.1, 0.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 times, etc., the thickness T1 of the main body portion 21. In addition, the main body portion 21 in the embodiments of the present application may have a constant thickness structure or a non-uniform thickness structure. If the main body portion 21 has a constant thickness structure, the thickness at positions other than the weak region 211 of the main body portion 21 is a constant value, and this value is referred to as the thickness T1. If the main body portion 21 has a non-uniform thickness structure, the average value of the thickness at positions other than the weak region 211 of the main body portion 21, i.e., the average thickness, is referred to as the thickness T1.

[0121] By setting W1 to be not less than 0.1T1 and not more than 5T1, and W2 to be not less than 0.5T1 and not more than 8T1, the processing and forming of the mounting portion 22 are facilitated. The connecting segment 222 has a relatively uniform wall thickness, a stable form, relatively good stability of force action, and by obtaining a first planar segment 2221 with a larger area, the stability of the contact and support engagement between the mounting portion 22 and the groove bottom wall 321 is further improved, and it is advantageous to further increase the contact area of heat transfer and vibration transfer between the mounting portion 22 and the groove bottom wall 321.

[0122] Please refer to FIGS. 6 and 7 again. In some embodiments of the present application, the radial width W1 of the second planar segment 2222 is smaller than the radial width W2 of the first planar segment 2221. At the same time, the radial width W2 of the first planar segment 2221 is 0.5 to 8 times the wall thickness T1 of the main body portion 21, and the radial width W1 of the second planar segment 2222 is 0.1 to 5 times the wall thickness T1 of the main body portion 21. That is, when selecting W1 from 0.1T1 to 5T1 and selecting W2 from 0.5T1 to 8T1, it is necessary to simultaneously satisfy W1 < W2, whereby the processing and molding of the mounting portion 22 can be facilitated. The connecting segment 222 has a relatively uniform wall thickness, a stable form, relatively good stability of force action, and the first planar segment 2221 has a larger area, so as to more effectively achieve surface contact with the groove bottom wall 321, further improving the stability of the contact and support engagement between the mounting portion 22 and the groove bottom wall 321, and further increasing the contact area of heat transfer and vibration transfer between the mounting portion 22 and the groove bottom wall 321.

[0123] For example, the value of W1 may be in the range of 0.3 mm to 1 mm, for example, W1 may be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., and the value of W2 may be in the range of 1 mm to 1.5 mm, for example, W2 may be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc., which facilitates the processing and molding of the mounting portion 22. The connecting segment 222 has a relatively uniform thickness, a stable shape, and relatively good stability in force application. Furthermore, the first planar segment 2221 has a larger area, which provides more effective surface contact with the groove bottom wall 321, thereby further improving the stability of the contact and supporting engagement between the mounting portion 22 and the groove bottom wall 321 and further increasing the contact area for heat transfer and vibration transmission between the mounting portion 22 and the groove bottom wall 321.

[0124] 6 and 7 again. In some embodiments of the present application, the dimensions of the mounting portion 22 satisfy Condition 1, in which the wall thickness T3 of the connection segment 222 is 0.75 to 1.2 times the wall thickness T1 of the main body portion 21, for example, 0.75, 0.85, 0.95, 1, 1.05, 1.1, 1.15, 1.2 times, etc. Note that the connection segment 222 may have either a constant thickness structure or a non-uniform thickness structure. In the case of a constant thickness structure, the wall thickness of the connection segment 222 is a constant value, and this value is referred to as the wall thickness T3. In the case of a non-uniform thickness structure, the average value of the wall thicknesses of the connection segment 222, i.e., the average wall thickness, is referred to as the wall thickness T3.

[0125] By setting T3 to be equal to or greater than 0.75T1 and equal to or less than 1.2T1, the thickness of the connecting segment 222 is not too thin, which improves the reliability of support and contact with the groove bottom wall 321, while the thickness of the connecting segment 222 is not too thick, which is advantageous in leaving the relief groove 224 relatively sufficient depth so that the relief groove 224 can effectively perform the function of releasing tensile stress.

[0126] For example, the value of T3 may be in the range of 0.4 mm to 0.6 mm, for example, T3 may be 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, etc., so that the thickness of the connecting segment 222 is not too thin, which improves the reliability of support and contact with the groove bottom wall 321, while the thickness of the connecting segment 222 is not too thick, which is advantageous in leaving a relatively sufficient depth for the relief groove 224 so that the relief groove 224 can effectively perform the function of releasing tensile stress.

[0127] 6 and 7 again. In some embodiments of the present application, the dimensions of the mounting portion 22 satisfy Condition 2, in which the axial depth H2 of the relief groove 224 is 0.5 to 3 times, for example, 0.5, 1, 1.5, 2, 2.5, or 3 times the thickness T1 of the main body portion 21. Note that the "axial depth of the relief groove 224" refers to the maximum depth of the opening 31 in the axial direction (for example, the first direction X shown in FIG. 6).

[0128] Thus, by setting H2 to be greater than or equal to 0.5T1 and less than or equal to 3T1, the depth of the relief groove 224 allows for good processability, and the shape of the processed relief groove 224 is relatively stable and reliable. Furthermore, since the depth of the relief groove 224 is not too shallow, the relief groove 224 can effectively exert the function of releasing tensile stress, while since the depth of the relief groove 224 is not too deep, a relatively sufficient thickness is left in the connecting segment 222, which is advantageous for improving the support and contact reliability between the connecting segment 222 and the groove bottom wall 321.

[0129] In addition, in some embodiments of the present application, the dimensions of the mounting portion 22 can simultaneously satisfy the above conditions 1 and 2, so that the depth of the undercut groove 224 allows for good processability, the shape of the processed undercut groove 224 is relatively stable and reliable, the undercut groove 224 can effectively release tensile stress, and the support and contact between the connecting segment 222 and the groove bottom wall 321 increases reliability.

[0130] Please refer to FIG. 5 again. In some embodiments of the present application, a projection of the weakened region 211 on the mounting portion 22 along the radial direction of the opening 31 (e.g., the second direction Y shown in FIG. 5 ) is located within the relief groove 224. For example, if the weakened region 211 is formed in the form of a lightening groove, an orthogonal projection of the lightening groove along the radial direction of the opening 31 is located within the relief groove 224. As a result, when welding stress between the welded segment 223 and the groove side wall 322 is transmitted toward the weakened region 211 along the radial direction of the opening 31, the installation position of the relief groove 224 can eliminate at least a portion of the force transmission path along the radial direction, thereby releasing the welding stress transmitted toward the weakened region 211 and thereby more effectively alleviating the adverse effects of the welding stress on the weakened region 211.

[0131] Please refer to Fig. 5 again. In some embodiments of the present application, the projection of the mounting portion 22 along the radial direction of the opening 31 of the main body portion 21 (e.g., the second direction Y shown in Fig. 5) is entirely within the relief groove 224. As a result, when welding stress between the welded segment 223 and the groove side wall 322 is transmitted along the radial direction of the opening 31 toward the weakened region 211, the installation position of the relief groove 224 makes it possible for the relief groove 224 to interrupt the force transmission path along the radial direction, thereby more sufficiently releasing the welding stress transmitted toward the weakened region 211 and thereby more effectively alleviating the adverse effects of the welding stress on the weakened region 211.

[0132] 5 and 6 again, in some embodiments of the present application, the connecting segment 222 and at least one of the cantilever segment 221 and the welding segment 223 are connected by a chamfer such as a C-chamfer or an R-chamfer, which can alleviate the problem of stress concentration caused by a large bend angle transition at the connection point, improve the structural reliability of the pressure relief valve plate 2, and make it less likely to suffer problems such as breakage when the pressure relief valve plate 2 is welded or subjected to force during operation.

[0133] For example, the chamfer may include at least one of a first chamfer 225, a second chamfer 226, a third chamfer 227, and a fourth chamfer 228, in which the surface of the connecting segment 222 facing the groove bottom wall 321 and the corresponding surface of the cantilever segment 221 may be connected by the first chamfer 225, the surface of the connecting segment 222 facing away from the groove bottom wall 321 and the corresponding surface of the cantilever segment 221 may be connected by the second chamfer 226, the surface of the connecting segment 222 facing away from the groove bottom wall 321 and the corresponding surface of the welding segment 223 may be connected by the third chamfer 227, and the surface of the connecting segment 222 facing the groove bottom wall 321 and the corresponding surface of the welding segment 223 may be connected by the fourth chamfer 228.

[0134] For example, the third chamfer 227 may be a R-chamfer, and the chamfer radius R1 may be 0.2 mm to 1 mm, for example, R1 may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., which can alleviate the problem of stress concentration at the connection point between the connecting segment 222 and the welded segment 223 when welding the welded segment 223 to the groove sidewall 322 and reduce the risk of fracture at the connection point between the connecting segment 222 and the welded segment 223, thereby allowing the welding stress to be effectively released by, for example, slight deformation of the mounting portion 22. For example, the second chamfer 226 and the first chamfer 225 may be a R-chamfer, and the chamfer radius may be equal to or close to the chamfer radius R1, which is easy to design and process and relatively reliable in alleviating the problem of stress concentration at the corresponding connection point.

[0135] 6 and 7 again, in some embodiments of the present application, one end of the cantilever segment 221 remote from the connecting segment 222 is bent and connected to the edge of the main body portion 21 (i.e., the pressure release valve plate 2 is bent to the connecting position of the cantilever segment 221 and the main body portion 21), so that the cantilever segment 221 is inclined with respect to the main body portion 21. For example, the cantilever segment 221 extends in a direction from the main body portion 21 to the connecting segment 222 at an incline with respect to the main body portion 21. As can be seen from this, the cantilever segment 221 and the main body 21 are not indirectly connected, but are directly connected, and further, by providing that the cantilever segment 221 extends obliquely relative to the main body 21 along the direction from the main body 21 to the connection portion, the cantilever segment 221 can be cantilevered over the opening 31 and / or the countersunk groove 32, and thus the main body 21 consists only of the cantilever segment 221, the connection segment 222 and the welded segment 223, which has a simple structure, occupies a small space and is easy to process.

[0136] Of course, the present application is not limited thereto. For example, in other embodiments of the present application, another structure may be connected between the main body portion 21 and the cantilever segment 221. That is, the attachment portion 22 may further include a transition segment for indirectly connecting the cantilever segment 221 and the main body portion 21. For example, the transition segment may extend along a straight line, a diagonal line, a curved line, or a fold line. If the transition segment is bent, it can further reduce the internal stress or external force transmitted from the attachment portion 22 to the main body portion 21 and further reduce the adverse effect on the weakened region 211 in the main body portion 21. For example, the attachment portion 22 may extend along a line approximating a "U," "V," "W," "M," or "N" shape in the radial direction of the opening 31, away from the main body portion 21.

[0137] 6 and 7 again for illustrative purposes. When one end of the cantilever segment 221, which is farther from the connecting segment 222, is connected to the edge of the main body 21, the axial step H1 between the surface of the main body 21 on the thickness side closer to the groove bottom wall 321 and the first flat segment 2221 is 0.5 to 2 times the wall thickness T1 of the main body 21, for example, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2 times, etc. Note that the "axial step H1" refers to the average value of the step in the axial direction of the opening 31 (for example, the first direction X shown in FIG. 6). For example, the lower surface of the main body 21 and the lower surface of the connecting segment 222 shown in FIG. 7 are both horizontal surfaces, and the step in the vertical direction between these two horizontal surfaces is the axial step H1.

[0138] By setting H1 to be greater than or equal to 0.5T1 and less than or equal to 2T1, the extension distance of the cantilever segment 221 in the axial direction of the opening 31 is not too short, which makes it easy to release welding stress at the opening position and depth of the relief groove 224, and the connecting segment 222 has a certain thickness so that it can reliably contact and support the groove bottom wall 321. On the other hand, not extending the cantilever segment 221 in the axial direction of the opening 31 in such a way that it is advantageous to reduce the space occupied by the pressure release valve plate 2 in the axial direction of the opening 31, improve the structural compactness of the battery cell 20, and increase the energy density per unit volume of the battery cell 20.

[0139] For example, the value of H1 may be in the range of 0.3 mm to 1 mm, for example, H1 may be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., so that the extension distance of the cantilever segment 221 in the axial direction of the opening 31 is not too short, which makes it easy to release welding stress at the opening position and depth of the relief groove 224, and the connecting segment 222 has a certain thickness so that it can reliably contact and support the groove bottom wall 321. On the other hand, not extending the cantilever segment 221 in the axial direction of the opening 31 in such a way that it is advantageous to reduce the space occupied by the pressure release valve plate 2 in the axial direction of the opening 31, which is advantageous to improve the structural compactness of the battery cell 20 and the energy density per unit volume of the battery cell 20.

[0140] 6 and 7 again for examples. When one end of the cantilever segment 221 remote from the connecting segment 222 is connected to the edge of the main body portion 21, the wall thickness T4 of the cantilever segment 221 is equal to or greater than the wall thickness T1 of the main body portion 21. Note that the cantilever segment 221 may have either a constant thickness structure or a non-uniform thickness structure. When the cantilever segment 221 has a constant thickness structure, the wall thickness of the cantilever segment 221 is a constant value, and this value is taken as the wall thickness T4. When the cantilever segment 221 has a non-uniform thickness structure, the average value of the wall thicknesses of the cantilever segment 221, i.e., the average wall thickness, is taken as the wall thickness T4.

[0141] As a result, by setting the thickness T4 of the cantilever segment 221 to be equal to or greater than the thickness T1 of the main body 21, the cantilever segment 221 has a relatively large thickness, which can more effectively balance the overall force acting on the pressure release valve plate 2 during the welding and operation process and better exert the functions of releasing stress and absorbing vibration, thereby better protecting the fragile area 211 from the effects of welding stress and improving the stability and reliability of the operation of the pressure release valve plate 2.

[0142] 6 and 7 again for examples. The wall thickness T4 of the cantilever segment 221 is 1.1 to 1.8 times the wall thickness T1 of the main body portion 21, for example, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, or 1.8 times. By setting T4 to be equal to or greater than 1.1T1 and equal to or less than 1.8T1, the difference in wall thickness between the cantilever segment 221 and the main body portion 21 is not too large, thereby improving the processability of the pressure relief valve plate 2. Meanwhile, the requirement that the wall thickness of the cantilever segment 221 be greater than that of the main body portion 21 can be satisfied. Therefore, the cantilever segment 221 effectively balances the force acting on the entire pressure relief valve plate 2 during welding and operation, effectively releasing stress and cushioning vibration. This better protects the weak area 211 from the effects of welding stress, and improves the stability and reliability of the operation of the pressure relief valve plate 2.

[0143] Illustratively, the value of T1 may be in the range of 0.3 mm to 0.4 mm, and the value of T4 may be in the range of 0.4 mm to 1 mm, for example, T4 may be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., which is advantageous to improving the processability of the pressure relief valve plate 2, and the cantilever segment 221 effectively balances the force acting on the entire pressure relief valve plate 2 during the welding and operation process, and effectively exerts the functions of stress relief and vibration buffering, thereby better protecting the weak area 211 from the effects of welding stress, and improving the stability and reliability of the operation of the pressure relief valve plate 2.

[0144] Of course, the present application is not limited thereto, and depending on the specifications of the battery cell 20, the range of the value of T1 may be further extended to 0.3 mm to 2 mm or more, so that the dimensions of the mounting portion 22 can be adjusted accordingly according to T1, and this will not be described again here.

[0145] 4 to 6 again for some embodiments of the present application. The main body 21 and the cantilever segment 221 are connected by chamfering, such as C-chamfering or R-chamfering. This solves the problem of stress concentration due to a large bend angle transition at the connection point and improves the reliability of stress or vibration absorption by the cantilever segment 221. When the pressure relief valve plate 2 is subjected to force during welding or operation, problems such as breakage are unlikely to occur at the connection point between the main body 21 and the cantilever segment 221, improving the reliability of the connection between the mounting portion 22 and the main body 21. As a result, the cantilever segment 221 can relatively effectively relieve stress and absorb vibration, and the cantilever segment 221 can effectively balance the force acting on the entire pressure relief valve plate 2 during the welding and operation processes.

[0146] For example, the chamfers may include a fifth chamfer 2291 and / or a sixth chamfer 2292, in which the surface on the thickness side of the main body 21, for example the surface farther from the connecting segment 222, and the surface on the corresponding side of the cantilever segment 221 may be connected by the fifth chamfer 2291, and the surface on the other side of the thickness of the main body 21, for example the surface closer to the connecting segment 222, and the surface on the corresponding side of the cantilever segment 221 may be connected by the sixth chamfer 2292.

[0147] For example, the fifth chamfer 2291 may be a R-chamfer, and the chamfer radius R2 may be 0.2 mm to 2 mm, for example, R2 may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc., thereby improving the processing quality of the connection between the mounting part 22 and the cantilever segment 221, effectively alleviating the problem of stress concentration at the connection between the cantilever segment 221 and the main body 21, and improving the reliability of the connection between the mounting part 22 and the main body 21. This allows the cantilever segment 221 to more effectively relieve stress and absorb vibration, and improves the effect of the cantilever segment 221 in balancing the force acting on the entire pressure relief valve plate 2 during the welding and operation process.

[0148] For example, the sixth chamfer 2292 may be a R-chamfer, with the chamfer radius being smaller than the chamfer radius R2, which facilitates the thickening effect at the transition from the main body 21 to the cantilever segment 221, i.e., the wall thickness T4 of the cantilever segment 221 being equal to or greater than the wall thickness T1 of the main body 21. This not only further improves the processing quality of the connection between the mounting portion 22 and the cantilever segment 221, but also increases the wall thickness of the cantilever segment 221, which more effectively relieves stress and damps vibration, and improves the effect of the cantilever segment 221 in balancing the force acting on the entire pressure relief valve plate 2 during welding and operation.

[0149] In some embodiments of the present application, please refer to FIG. 4 again. At least the end of the weld segment 223 far from the groove bottom wall 321 in the axial direction of the opening 31, e.g., in the first direction X shown in FIG. 4, e.g., at least the upper end of the weld segment 223 shown in FIG. 4, is heat-welded as a whole as a weld mark. For example, the hatched area shown in FIG. 4 indicates the heat-welded portion, and the weld mark thereby defines a partial groove wall of the undercut groove 224. That is, after welding the pressure relief valve plate 2 and the mounting fixture 3, the undercut groove 224 still exists, and the weld mark defines a partial groove wall of the undercut groove 224. This explains that the undercut groove 224 has sufficient dimensions and is always available for stress relief during the welding process, which is advantageous for increasing the effectiveness of micro-deformation of the cantilever segment 221 and the weld segment 223 and provides a protective effect for reducing stress transmission to the weak region 211.

[0150] 6 and 7 again, in some embodiments of the present application, the thickness T2 of the welded segment 223 is 0.75 to 1.5 times the thickness T1 of the main body 21, for example, 0.75, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5 times, etc. Note that the welded segment 223 may have either a constant thickness structure or a non-uniform thickness structure. In the case of a constant thickness structure, the thickness of the welded segment 223 is a constant value, and this value is referred to as the thickness T2. In the case of a non-uniform thickness structure, the average value of the thicknesses of the welded segment 223, i.e., the average thickness, is referred to as the thickness T2.

[0151] Therefore, when welding the weld segment 223 to the groove side wall 322 of the countersunk groove 32, by setting T2 to be 0.75T1 or more and 1.5T1 or less, the thickness of the weld segment 223 is not too thin and is relatively thick enough for thermal welding, resulting in relatively high connection reliability after welding. On the other hand, the thickness of the weld segment 223 is not too thick, so that the molten pool formed when welding the weld segment 223 spreads into the relief groove 224, which is advantageous in improving the fluidity of the molten pool, improving welding quality, releasing welding stress, and reducing the adverse effects of welding stress on the weak area 211.

[0152] For example, the value of T2 may be in the range of 0.5 mm to 1 mm. For example, T2 may be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., which is advantageous in that the thickness of the welded segment 223 is not too thin and has a relatively sufficient thickness for thermal welding, resulting in relatively high connection reliability after welding. On the other hand, the thickness of the welded segment 223 is not too thick, which allows the molten pool formed during welding of the welded segment 223 to spread into the relief groove 224, thereby improving the fluidity of the molten pool, improving weld quality, releasing welding stress, and reducing the adverse effects of welding stress on the weak area 211.

[0153] 4 and 6 again, one surface of the two surfaces of the weld segment 223 in the thickness direction faces the relief groove 224, and the other surface faces the groove side wall 322 of the countersunk groove 32, and the wall surface of the weld segment 223 facing the groove side wall 322 in the thickness direction is the weld side wall 2231. In some embodiments of the present application, the weld side wall 2231 includes a weld wall segment 22311 and a guide wall segment 22312, and the guide wall segment 22312 is connected to a side of the weld wall segment 22311 that is closer to the groove bottom wall 321, and the guide wall segment 22312 extends at an angle toward the groove bottom wall 321 and gradually approaches the main body 21 relative to the weld wall segment 22311. For example, the guide wall segment 22312 may extend at an angle along an oblique line or a curved line.

[0154] As a result, when the mounting portion 22 is mounted in the countersunk groove 32, the guide wall segment 22312 narrows inward relative to the welded wall segment 22311, thereby providing a guide for the guide wall segment 22312, improving the mounting efficiency of the pressure release valve plate 2 and the mounting fixture 3 and allowing for smooth mounting. Meanwhile, the welded wall segment 22311 widens outward relative to the guide wall segment 22312, allowing for stable engagement between the welded wall segment 22311 and the groove side wall 322 of the countersunk groove 32, thereby improving the yield of welding of both. For example, by arranging the welded wall segment 22311 to match the shape of the groove side wall 322 of the countersunk groove 32, the two can engage or interference-engage with each other with a relatively small gap, further improving the yield of welding of both.

[0155] 6 again for an example. When the mounting portion 22 includes the fourth chamfer 228, the fourth chamfer 228 can be formed into a C-chamfer or an R-chamfer to form the guide wall segment 22312. Therefore, when the guide wall segment 22312 is provided, the problem of stress concentration at the connection point between the welding segment 223 and the connection segment 222 can also be improved.

[0156] 6 and 7 again. In some embodiments of the present application, the dimensions of the mounting portion 22 satisfy Condition 4, in which the axial height H4 of the welding side wall 2231 is 1 to 5 times, for example, 1, 2, 3, 4, or 5 times, the thickness T1 of the main body portion 21. Note that the "axial height of the welding side wall 2231" refers to the height of the welding side wall 2231 in the axial direction of the opening 31 (for example, the first direction X shown in FIG. 6), for example, the vertical distance in the up-down direction between the upper and lower ends of the welding side wall 2231 shown in FIG. 6.

[0157] Thus, by setting H4 to be greater than or equal to T1 and less than or equal to 5T1, when the welding side wall 2231 is welded to the groove side wall 322 of the countersunk groove 32, the axial height of the welding side wall 2231 is not too short and can be relatively long enough to provide the welding wall segment 22311 and the guide wall segment 22312, which is advantageous for optimizing the welding effect of the welding wall segment 22311 and the guiding effect of the guide wall segment 22312. On the other hand, since the axial height of the welding side wall 2231 is not too long, the depth of the countersunk groove 32 engaged with the welding side wall 2231 can be reduced, which is advantageous for reducing the thickness of the fixture 3, and is advantageous for a lightweight design and reducing the space occupied by the fixture 3.

[0158] Illustratively, the value of H4 may be in the range of 0.6 mm to 2 mm, for example, H4 may be 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc., whereby the axial height of the welded side wall 2231 is not too short and has a relatively sufficient length to provide the welded wall segment 22311 and the guide wall segment 22312, which is advantageous for optimizing the welding effect of the welded wall segment 22311 and the guiding effect of the guide wall segment 22312. On the other hand, where the axial height of the welded side wall 2231 is not too long, the depth of the countersunk groove 32 engaged with the welded side wall 2231 can be reduced, which is advantageous for reducing the thickness of the fixture 3, which is advantageous for a lightweight design, and for reducing the space occupied by the fixture 3.

[0159] In some embodiments of the present application, T3 + H2 = H4, and the thickness T3 of the connecting segment 222 is set to 0.75 to 1.2 times the thickness T1 of the main body 21, and the axial depth H2 of the relief groove 224 is set to 0.5 to 3 times the thickness T1 of the main body 21. In this case, the axial height of the welded side wall 2231 is not too short and can be relatively long enough to provide the welded wall segment 22311 and the guide wall segment 22312, which is advantageous for optimizing the welding effect of the welded wall segment 22311 and the guiding effect of the guide wall segment 22312. Meanwhile, since the axial height of the welded side wall 2231 is not too long, the depth of the countersunk groove 32 engaged with the welded side wall 2231 can be reduced, which is advantageous for reducing the thickness of the fixture 3, and is advantageous for a lightweight design and reducing the space occupied by the fixture 3.

[0160] 6 and 7 again. In some embodiments of the present application, the dimensions of the mounting portion 22 satisfy Condition 5, in which the axial height H3 of the welded wall segment 22311 is 0.5 to 3 times, for example, 0.5, 1, 1.5, 2, 2.5, or 3 times the wall thickness T1 of the main body portion 21. Note that the "axial height of the welded wall segment 22311" refers to the elevation of the opening 31 of the welded wall segment 22311 in the axial direction (for example, the first direction X shown in FIG. 6), for example, the vertical distance in the up-down direction between the upper and lower ends of the welded wall segment 22311 shown in FIG. 6.

[0161] Thus, by setting H3 to be greater than or equal to 0.5T1 and less than or equal to 3T1, when welding the welded wall segment 22311 to the groove side wall 322 of the countersunk groove 32, the axial height of the welded wall segment 22311 is not too short and can have a relatively sufficient length for thermal welding, resulting in relatively high connection reliability after welding. On the other hand, because the axial height of the welded wall segment 22311 is not too long, the depth of the countersunk groove 32 welded to the welded wall segment 22311 can be reduced, which is advantageous for reducing the thickness of the fixture 3 and is advantageous for a lightweight design and reducing the space occupied by the fixture 3.

[0162] For example, the axial height H3 of the welded wall segment 22311 may be further specified to be 0.5 to 2.4 times the wall thickness T1 of the main body portion 21, for example, 0.5, 1, 1.5, 2, 2.4 times, etc., which further ensures that the axial height of the welded wall segment 22311 is not too long and further reduces the depth of the countersunk groove 32 welded to the welded wall segment 22311, which is advantageous for reducing the thickness of the fixture 3 and for achieving a lightweight design and reducing the space occupied by the fixture 3.

[0163] For example, the value of H3 may be in the range of 0.5 mm to 1.2 mm. For example, H3 may be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, etc., so that the axial height of the welded wall segment 22311 is not too short and has a relatively sufficient length for thermal welding, resulting in relatively high connection reliability after welding. On the other hand, because the axial height of the welded wall segment 22311 is not too long, the depth of the countersunk groove 32 welded to the welded wall segment 22311 can be reduced, which is advantageous for reducing the thickness of the fixture 3, and is advantageous for a lightweight design and reducing the space occupied by the fixture 3.

[0164] 6 and 7 again. In some embodiments of the present application, the dimensions of the mounting portion 22 satisfy Condition 6, in which the radial width W3 of the guide wall segment 22312 in the orthogonal projection along the axial direction of the opening 31 is 0.1 to 0.5 times, for example, 0.1, 0.2, 0.3, 0.4, or 0.5 times the wall thickness T1 of the main body portion 21. Note that the "radial width W3 of the guide wall segment 22312 in the orthogonal projection along the axial direction of the opening 31" refers to the dimension of the guide wall segment 22312 in the radial direction of the opening 31, e.g., the second direction Y shown in FIG. 6, in the orthogonal projection along the axial direction of the opening 31 (e.g., the first direction X shown in FIG. 6), e.g., the horizontal distance between the left and right ends of the guide wall segment 22312 shown in FIG. 6.

[0165] Therefore, by setting W3 to be greater than or equal to 0.1T1 and less than or equal to 0.5T1, the radial width of the guide wall segment 22312 is not too small, and a relatively effective guiding effect can be achieved. On the other hand, when the radial widths of the mounting portion 22 and the cantilever segment 221 are constant, the radial width of the guide wall segment 22312 is not too large, and space is left to allow the radial width of the connecting segment 222 to be increased, thereby improving the stability of the contact support between the connecting segment 222 and the groove bottom wall 321 and improving the positioning effect and welding quality when the pressure relief valve plate 2 is attached to the mounting fixture 3.

[0166] For example, the value of W3 may be in the range of 0.2 mm to 0.4 mm, for example, W3 may be 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, etc., so that the radial width of the guide wall segment 22312 is not too small and can have a relatively effective guiding effect. On the other hand, when the radial widths of the mounting portion 22 and the cantilever segment 221 are constant, the radial width of the guide wall segment 22312 configured as above is not too large, so that a space is left to increase the radial width of the connecting segment 222, thereby improving the stability of the contact support between the connecting segment 222 and the groove bottom wall 321 and improving the positioning effect and welding quality when the pressure relief valve plate 2 is attached to the mounting fixture 3.

[0167] In addition, in some embodiments of the present application, the dimensions of the mounting portion 22 can simultaneously satisfy the above conditions 4 and 5, thereby making it possible to ensure that the axial length of the guide wall segment 22312 is neither too long nor too short, thereby improving the guiding effect while satisfying processability.

[0168] Please refer to Figures 8 to 11. Figure 8 is a cross-sectional view of an application of a pressure relief member 201 according to some embodiments of the present application, Figure 9 is a cross-sectional view of an application of a pressure relief member 201 according to other some embodiments of the present application, Figure 10 is a cross-sectional view of an application of a pressure relief member 201 according to still further some embodiments of the present application, and Figure 11 is a cross-sectional view of an application of a pressure relief member 201 according to still further some embodiments of the present application. In some embodiments of the present application, the mounting fixture 3 has a first side and a second side in the thickness direction, and the countersunk groove 32 is formed in an end wall of the first side of the mounting fixture 3, and the groove opening 323 of the countersunk groove opens toward the first side, or the countersunk groove 32 is formed in an end wall of the second side of the mounting fixture 3, and the groove opening 323 of the countersunk groove opens toward the second side.

[0169] For example, the first side of the fixture 3 is the inside, which is suitable for forming the accommodating chamber 13, and the accommodating chamber 13 may be used to mount the electrode assembly of the battery cell 20. The side of the fixture 3 away from the accommodating chamber 13 is the second side, i.e., the outside of the fixture 3. In this case, the inner wall of the fixture 3 forms the end wall of the first side, and the outer wall of the fixture 3 forms the end wall of the second side. For example, in combination with FIG. 3 , if the housing 1 of the battery cell 20 includes a body 11 and a cover 12, the accommodating chamber 13 is formed between the body 11 and the cover 12, and both the body 11 and the cover 12 may be the fixture 3. The wall surface of the fixture 3 facing the accommodating chamber 13 is the inner wall, and the wall surface of the fixture 3 away from the accommodating chamber 13 is the outer wall.

[0170] 8 and 9, in some embodiments of the present application, the countersunk groove 32 is formed on the inner wall of the mounting fixture 3, and the groove opening 323 of the countersunk groove opens toward the accommodating chamber 13. At this time, the groove opening of the relief groove 224 also opens toward the accommodating chamber 13, thereby realizing support for the connecting segment 22 and the groove bottom wall 321. This allows the pressure release valve plate 2 to be attached to the side of the mounting fixture 3 facing the accommodating chamber 13. For example, the pressure release valve plate 2 and the mounting fixture 3 can be welded together first, and then other components of the battery cell 20 can be assembled.

[0171] 10 and 11 , in some other embodiments of the present application, the countersunk groove 32 is formed on the outer wall of the mounting fixture 3, and the groove opening 323 of the countersunk groove opens in a direction away from the accommodating chamber 13, and the groove opening of the relief groove 224 also opens in a direction away from the accommodating chamber 13, thereby realizing support for the connecting segment 22 and the groove bottom wall 321. This allows the pressure release valve plate 2 to be attached to the side of the mounting fixture 3 that faces away from the accommodating chamber 13. For example, other components of the battery cell 20 can be assembled first, and then the pressure release valve plate 2 and the mounting fixture 3 can be welded together last.

[0172] As a result, the pressure release valve plate 2 in the embodiments of the present application is not limited to being attached to the inside or outside of the mounting fixture 3, which allows for flexible installation of the pressure release valve plate 2, meets the installation needs of different types of mounting fixtures 3, and diversifies the situations in which the pressure release valve plate 2 can be used. When the pressure release valve plate 2 is installed on the side of the mounting fixture 3 away from the accommodating chamber 13, it is possible to more effectively prevent conductive metal such as slag from falling into the accommodating chamber 13, thereby improving the reliability of the battery cells 20.

[0173] 12, which is a structural schematic diagram of a pressure relief valve plate 2 according to some other embodiments of the present application. In some embodiments of the present application, the weakened area 211 is a lightening groove 23, which has a blind groove shape and opens in the same direction as the opening direction of the relief groove 224, as shown in FIGS. 8 and 10, or in the opposite direction, as shown in FIGS. 9 and 11. This allows the opening direction of the lightening groove 23 and the opening direction of the relief groove 224 to be the same or opposite, thereby realizing flexible processing of the pressure relief valve plate 2 and further meeting the needs of different applications and diversifying the applicable scenarios of the pressure relief valve plate 2. Furthermore, when the lightening groove 23 opens toward the receiving chamber 13, it can serve as a buffer structure to accommodate generated gas.

[0174] In some embodiments of the present application, the contour line of the lightening groove 23 (i.e., the contour line of the lightening groove 23 as orthogonally projected on the main body 21 along the axial direction of the opening 31) is an open ring that is identical to and concentric with the contour shape of the pressure release valve plate 2. In other words, on a projection plane perpendicular to the axial direction of the opening 31, the contour line of the lightening groove 23 is the contour line of the ring line that is slightly smaller (which may be an integer multiple, but is not limited to this) than the contour line of the pressure release valve plate 2. For example, if the contour shape of the pressure release valve plate 2 is track-shaped, the contour line of the lightening groove 23 is a track-shaped contour line with an opening; if the contour shape of the pressure release valve plate 2 is elliptical, the contour line of the lightening groove 23 is an elliptical contour line with an opening; and if the contour shape of the pressure release valve plate 2 is rectangular, the contour line of the lightening groove 23 is a rectangle with an opening. The distance between the center of the lightening groove 23 and the mounting portion 22 is larger than the distance between the lightening groove 23 and the edge of the mounting portion 22, i.e., the lightening groove 23 is provided closer to the edge of the mounting portion 22 than to the center of the mounting portion 22, i.e., when any radial line of the pressure release valve plate 2 is drawn on the projection plane, the distance between the lightening groove 23 and the center of the mounting portion 22 on the radial line (for example, distance a shown in FIG. 12) is larger than the distance between the lightening groove 23 and the edge of the mounting portion 22 on the radial line (for example, distance b shown in FIG. 12), i.e., a is larger than b. This simplifies the die line of the lightening groove 23, making it easier to process, and furthermore, enabling the valve to open more reliably.

[0175] The shape of the contour line of the lightening groove 23 is not limited to these, and for example, the shape of the orthogonal projection of the lightening groove 23 on the main body 21 along the axial direction of the opening 31 may be a shape of two intersecting lines or a hyperbolic shape.

[0176] In some embodiments of the present application, the pressure relief valve plate 2 has the mounting portion 22 and the main body portion 21 formed by press-molding, and the main body portion 21 has a flat plate structure with constant thickness. This simplifies the manufacturing process of the pressure relief valve plate 2, and makes it easy to ensure that the thickness of the mounting portion 22 at each position meets the design requirements. Furthermore, because the bent shape of the mounting portion 22 can protect the fragile area 211, the main body portion 21 does not need to be specially processed to protect the fragile area 211, and only needs to have a flat plate structure with constant thickness, which is advantageous in simplifying the structure and processing of the main body portion 21.

[0177] In addition, the fragile region 211 may be processed and molded together with the main body portion 21, for example, by press molding together, or may be processed into the main body portion 21 after the main body portion 21 has been processed and molded, for example, the fragile region 211 may be processed by a method such as subsequent laser ablation, and the present application is not limited to this.

[0178] 3 and 4 again, according to some embodiments of the present application. The present application further provides a battery cell 20 including a housing 1 and an electrode assembly, the electrode assembly being disposed within the housing 1, the housing 1 including a pressure release member 201 according to any one of the above embodiments. The pressure release member 201 according to the embodiments of the present application is advantageous in improving the reliability and stability of operation of the battery cell 20.

[0179] 3 and 4 again, according to some embodiments of the present application. The housing 1 includes a body 11 and a cover 12. The cover 12 is provided to cover the body 11 in an open position, and one of the body 11 and the cover 12 constitutes the mounting fixture 3. That is, the pressure relief valve plate 2 can be attached to either the body 11 or the cover 12, which allows for flexible selection of the mounting position of the pressure relief valve plate 2, thereby improving the flexibility of the design of the battery cell 20.

[0180] 8 to 11 again for some embodiments of the present application. An insulator 4 may be further provided inside the fixture 3, and the insulator 4 may be used to isolate the electrical connection members in the accommodation chamber 13 from the fixture 3 to reduce the risk of short circuit. For example, the insulator 4 may be made of plastic, rubber, or the like.

[0181] According to some embodiments of the present application, the present application further provides a battery 100 including one or more of the battery cells 20 of any one of the above embodiments. The battery cells 20 of the embodiments of the present application have improved operational reliability and stability, which is advantageous for improving the operational reliability and stability of the battery 100.

[0182] According to some embodiments of the present application, the present application further provides an electric device including the battery 100 of any one of the above embodiments, where the battery 100 is used to provide electric energy to the electric device. The battery 100 of the embodiments of the present application has improved operational reliability and stability, which is advantageous for improving the operational reliability and stability of the electric device.

[0183] 3 to 7 and 10 for some embodiments of the present application. A battery cell 20 is provided, the battery cell 20 including a housing 1 and an electrode assembly, the housing 1 including a body 11 and a cover 12, the cover 12 being provided to cover the body 11 in an open position, thereby defining a storage chamber 13 between the body 11 and the cover 12, and the electrode assembly being provided in the storage chamber 13. The cover 12 has an opening 31, and a counterbore groove 32 is provided in the cover 12 surrounding the opening 31 in a circumferential direction, the counterbore groove 32 including a groove bottom wall 321 and a groove side wall 322, the counterbore groove 32 being formed on an outer wall of the cover 12, and a groove opening 323 of the counterbore groove opening in a direction away from the storage chamber 13. A pressure release valve plate 2 is provided on the cover 12, and the pressure release valve plate 2 is provided to cover the opening 31 and includes a main body portion 21 and an attachment portion 22. The main body portion 21 has a flat plate structure of equal thickness and has a weak area 211 in the form of a lightening groove 23. The attachment portion 22 is connected to the outer periphery of the main body portion 21 and is bent so as to be supported by the groove bottom wall 321 and welded to the groove side wall 322.

[0184] Among these, the mounting portion 22 includes a cantilever segment 221, a connection segment 222, and a welded segment 223, which are connected sequentially from the inside to the outside in the radial direction of the opening 31, and the connection segment 222 is connected to the cantilever segment 221 and the welded segment 223 by chamfering. The connection segment 222 is supported by the groove bottom wall 321, and the cantilever segment 221 is cantilevered above the opening 31 and / or the countersunk groove 32, and the cantilever segment 221 and the welded segment 223 both extend toward the groove opening 323 of the countersunk groove relative to the connection segment 222, thereby forming a relief groove 224 among the cantilever segment 221, the connection segment 222, and the welded segment 223, and the groove opening of the relief groove 224 also opens in the direction away from the accommodating chamber 13, and the orthogonal projection of the weakened region 211 along the radial direction of the opening 31 is within the relief groove 224, and the welded segment 223 is welded to the groove side wall 322.

[0185] The surface of the connecting segment 222 facing the groove bottom wall 321 includes a first planar segment 2221, which is an annular plane surrounding the entire circumference of the main body portion 21, and the first planar segment 2221 is in face contact with and supported by the groove bottom wall 321, and the surface of the connecting segment 222 away from the groove bottom wall 321 includes a second planar segment 2222, and the orthogonal projection of the second planar segment 2222 along the axial direction of the opening 31 is within the first planar segment 2221.

[0186] One end of the cantilever segment 221, remote from the connecting segment 222, is connected to the edge of the main body 21 by a chamfer, and the cantilever segment 221 extends obliquely relative to the main body 21 in the direction from the main body 21 to the connecting portion. At least the end of the welded segment 223, remote from the groove bottom wall 321, is heat-fused as a weld mark as a whole, thereby forming a partial groove wall of the relief groove 224 by the weld mark. The wall surface of the welded segment 223 facing the groove side wall 322 in the thickness direction is the welded side wall 2231. The welded side wall 2231 includes a welded wall segment 22311 and a guide wall segment 22312. The guide wall segment 22312 is connected to the side of the welded wall segment 22311 that is closer to the groove bottom wall 321, and the guide wall segment 22312 extends obliquely relative to the welded wall segment 22311 in the direction toward the groove bottom wall 321, gradually approaching the main body 21.

[0187] As a result, the battery cell 20 of this embodiment effectively reduces the adverse effects of welding tensile stress on the weak area 211 of the pressure release valve plate 2, improves the distribution of force acting on the pressure release valve plate 2 during its operation, makes the force acting more uniform, improves the vibration-damping and fatigue resistance of the pressure release valve plate 2, and ultimately improves the reliability and stability of the operation of the battery cell 20. In addition, because the pressure release valve plate 2 is attached to the side of the cover 12 away from the accommodating chamber 13, it is possible to relatively effectively prevent conductive metals such as slag from falling into the accommodating chamber 13, thereby improving the reliability of the battery cell 20.

[0188] In addition, in the case where there is no conflict, the embodiments and features of the embodiments in this application can be combined with each other.

[0189] The above is only a preferred embodiment of the present application, and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the concept and principles of the present application shall be included within the scope of protection of the present application. [Explanation of symbols]

[0190] Reference number Vehicle 1000, battery 100, controller 200, motor 300, case 10, first case body 101, second case body 102, battery cell 20, pressure release member 201, housing 1, body 11, cover 12, storage chamber 13, pressure release valve plate 2, main body 21, weak area 211, lightening groove 23, mounting portion 22, cantilever segment 221, connection segment 222, first planar segment 2221, second planar segment ment··2222, welded segment··223, welded side wall··2231, welded wall segment··22311, guide wall segment··22312, relief groove··224, first chamfer··225, second chamfer··226, third chamfer··227, fourth chamfer··228, fifth chamfer··2291, sixth chamfer··2292, mounting fixture··3, opening··31, counterbore groove··32, groove bottom wall··321, groove side wall··322, counterbore groove opening··323, insulator··4, first direction··X, second direction··Y.

Claims

1. A pressure release member for a battery cell, a mounting fixture having an opening and a countersunk groove including a groove bottom wall and a groove side wall provided in a circumferential direction surrounding the opening; a pressure release valve plate provided to cover the opening, the pressure release valve plate including a main body portion and an attachment portion, the main body portion having a weakened region, the attachment portion being connected to an outer periphery of the main body portion and being bent to be supported on the groove bottom wall and welded to the groove side wall; Battery cell pressure relief member.

2. The attachment portion includes a cantilever segment, a connection segment, and a welding segment, which are connected in sequence from the inside to the outside in the radial direction of the opening, the connection segment is supported on the groove bottom wall, the cantilever segment is cantilevered above the opening and / or the countersunk groove, and the cantilever segment and the welding segment are both bent relative to the connection segment toward the groove opening of the countersunk groove, thereby forming relief grooves between the cantilever segment, the connection segment, and the welding segment, and the welding segment is welded to the groove side wall. The pressure relief member of claim 1 .

3. a surface of the connecting segment facing the groove bottom wall includes a first planar segment, the first planar segment being in surface contact with and supported by the groove bottom wall; The pressure relief member of claim 2 .

4. The first planar segment is an annular planar surface that surrounds the entire circumference of the main body. The pressure relief member of claim 3 .

5. a surface of the connecting segment remote from the groove bottom wall includes a second planar segment, and at least a portion of a projection of the second planar segment on the first planar segment along an axial direction of the opening is within the first planar segment; The pressure release member according to claim 3 or 4.

6. The radial width of the second planar segment is smaller than the radial width of the first planar segment, and / or the radial width of the first planar segment is 0.5 to 8 times the wall thickness of the main body portion, and the radial width of the second planar segment is 0.1 to 5 times the wall thickness of the main body portion. The pressure relief member of claim 5 .

7. The wall thickness of the connection segment is 0.75 to 1.2 times the wall thickness of the main body portion, and / or the axial depth of the relief groove is 0.5 to 3 times the wall thickness of the main body portion. The pressure release member according to any one of claims 2 to 6.

8. a projection of the weakened region on the mounting portion along a radial direction of the opening is within the undercut groove; The pressure release member according to any one of claims 2 to 7.

9. a projection of the opening of the main body portion on the mounting portion along a radial direction thereof is entirely within the relief groove; The pressure relief member of claim 8.

10. The connection segment and at least one of the cantilever segment and the welding segment are connected by a chamfer. The pressure release member according to any one of claims 2 to 9.

11. an end of each cantilever segment that is farther from the connecting segment is bent and connected to an edge of the main body portion, thereby causing the cantilever segment to incline relative to the main body portion; The pressure release member according to any one of claims 2 to 10.

12. a step in the axial direction between a thickness side surface of the main body portion close to the groove bottom wall and a thickness side surface of the connecting segment close to the groove bottom wall is 0.5 to 2 times the wall thickness of the main body portion; The pressure relief member of claim 11.

13. The wall thickness of the cantilever segment is equal to or greater than the wall thickness of the main body portion.

13. The pressure relief member of claim 12.

14. The wall thickness of the cantilever segment is 1.1 to 1.8 times the wall thickness of the main body portion.

14. The pressure relief member of claim 13.

15. The main body and the cantilever segment are connected by a chamfer. The pressure release member according to any one of claims 11 to 14.

16. At least an end of the welded segment farther from the groove bottom wall is heat-welded as a weld mark as a whole, whereby the weld mark forms a partial groove wall of the relief groove. The pressure release member according to any one of claims 2 to 15.

17. The thickness of the welded segment is 0.75 to 1.5 times the thickness of the main body. The pressure release member according to any one of claims 2 to 16.

18. a wall surface of the welded segment facing the groove side wall in the thickness direction is a welded side wall, the welded side wall includes a welded wall segment and a guide wall segment, the guide wall segment is connected to the welded wall segment on the side closer to the groove bottom wall, and the guide wall segment extends in a direction toward the groove bottom wall, inclining toward the welded wall segment in a direction gradually approaching the main body portion; The pressure release member according to any one of claims 2 to 17.

19. The axial height of the welded side wall is 1 to 5 times the wall thickness of the main body portion, and / or the axial height of the welded wall segment is 0.5 to 3 times the wall thickness of the main body portion.

20. The pressure relief member of claim 18.

20. The radial width of the guide wall segment in an orthogonal projection along the axial direction of the opening is 0.1 to 0.5 times the wall thickness of the main body portion.

20. A pressure relief member according to claim 18 or 19.

21. The weakened region is a lightening groove, and an opening direction of the lightening groove and an opening direction of the relief groove are the same or opposite. The pressure release member according to any one of claims 2 to 20.

22. a contour line of the lightening groove is the same as a contour shape of the pressure release valve plate and is an open annular shape provided concentrically therewith, and a distance between the center of the lightening groove and the mounting portion is greater than a distance between the edge of the lightening groove and the mounting portion; 22. The pressure relief member of claim 21.

23. the mounting fixture has a first side and a second side in a thickness direction, and the countersunk groove is formed in an end wall of the mounting fixture on the first side, and the groove opening of the countersunk groove opens toward the first side, or the countersunk groove is formed in an end wall of the mounting fixture on the second side, and the groove opening of the countersunk groove opens toward the second side; A pressure release member according to any one of claims 1 to 22.

24. The pressure release valve plate has the mounting portion and the main body portion formed by press molding, and the main body portion has a uniform thickness flat plate structure. A pressure release member according to any one of claims 1 to 23.

25. A battery cell comprising a housing and an electrode assembly, the electrode assembly being provided within the housing, the housing comprising the pressure release member according to any one of claims 1 to 24. Battery cell.

26. The housing includes a body and a cover, the cover being configured to cover the body in an open position, and one of the body and the cover constituting the mounting fixture.

26. The battery cell of claim 25.

27. A battery comprising the battery cell of claim 25 or 26. battery.

28. 28. An electrical device comprising the battery of claim 27. Electrical equipment.

Images