CN218300006U - A shell, battery monomer, battery and power consumption device for battery monomer - Google Patents

Abstract

The application provides a shell, battery monomer, battery and with electric installation for battery monomer. The housing includes a pressure relief mechanism. Wherein, pressure relief mechanism includes: a body; the first weak part is arranged on the body and provided with two first free ends, and a connecting line of the two first free ends is not completely overlapped with the first weak part and defines a pressure relief part together; and the second weak part is arranged on the body, a first projection of the first weak part on a plane vertical to the first direction does not intersect with a second projection of the second weak part on the plane, the first direction is the thickness direction of the pressure relief part, and the pressure relief part is configured to be opened by taking the first weak part as a boundary and turn over towards one side where the second weak part is located when the pressure or the temperature inside the battery cell reaches a threshold value. The scheme of the embodiment of the application can improve the anti-damage ability of the pressure relief mechanism, promote the single effective pressure relief of the battery, and prolong the service life of the battery, thereby improving the safety of the battery.

Description

A shell, battery monomer, battery and power consumption device for battery monomer

Technical Field

The application relates to the technical field of batteries, in particular to a shell for a battery monomer, the battery monomer, a battery and an electric device.

Background

Energy conservation and emission reduction are the key points of sustainable development of the automobile industry, and the electric vehicle becomes an important component of the sustainable development of the automobile industry due to the advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in its development.

During charging and discharging and using of the battery, if the pressure or temperature inside the battery abnormally rises, safety problems easily occur, so that the service life of the battery is influenced, and even the personal safety of a user is influenced. Therefore, how to improve the safety of the battery is an important research and development direction.

SUMMERY OF THE UTILITY MODEL

The present application is directed to solving at least one of the problems in the prior art. Therefore, an object of the present application is to provide a housing for a battery cell, a battery and an electric device, so as to improve the safety of the battery.

Embodiments of a first aspect of the present application provide a housing for a battery cell, including a pressure relief mechanism. Wherein, pressure release mechanism includes: a body; the first weak part is arranged on the body and provided with two first free ends, and a connecting line of the two first free ends is not completely overlapped with the first weak part and defines a pressure relief part together; and the second weak part is arranged on the body, a first projection of the first weak part on a plane vertical to the first direction does not intersect with a second projection of the second weak part on the plane, the first direction is the thickness direction of the pressure relief part, and the pressure relief part is configured to be opened by taking the first weak part as a boundary and turn over towards one side where the second weak part is located when the pressure or the temperature inside the battery cell reaches a threshold value.

In the technical scheme of this application embodiment, set up two weak parts in pressure release mechanism for when pressure or the temperature of battery monomer inside reach the threshold value, pressure relief portion opens and overturns towards one side that another weak part place along one of them weak part. The above-described pressure relief mechanism defines the valve opening direction of the pressure relief mechanism in the direction in which one of the weak portions (i.e., the first weak portion) is broken, so that countermeasures are taken in advance, thereby improving the safety of the battery. The provision of the further frangible portion (i.e. the second frangible portion) can facilitate a quicker reversal of the pressure relief portion to the side of the frangible portion. In other words, compared with the technical scheme without the second weak portion, the second weak portion can enable the pressure relief portion to turn over a larger angle (turn over faster) in the same time, so that rapid and effective pressure relief of the battery cell is promoted.

In addition, in the above technical scheme, the projections of the first weak portion and the second weak portion on the plane perpendicular to the first direction are not intersected, so that stress concentration of the weak portions in an intersecting region can be avoided, the risk that the pressure relief mechanism starts to relieve pressure when the pressure in the battery cell does not reach the detonation pressure is reduced, the pressure relief mechanism is prevented from cracking in the intersecting region to cause inaccuracy of a valve opening direction, the anti-damage capability of the pressure relief mechanism is improved, the effective pressure relief of the battery cell is promoted, and the service life of the battery cell is prolonged.

Therefore, the shell that this application provided can improve the anti destructive power of pressure release mechanism, promotes the free effective pressure release of battery to improve the free life of battery, thereby improve the security of battery.

In some embodiments, the body has a first pressure relief groove and a second pressure relief groove formed thereon, the first weakened portion being a bottom wall of the first pressure relief groove, and the second weakened portion being a bottom wall of the second pressure relief groove. The weak part is arranged at the bottom of the pressure relief groove to form a position where the strength of the pressure relief mechanism is weak, so that the manufacturing and processing of the weak part can be facilitated.

In some embodiments, the first relief groove is located on a first surface of the body and the second relief groove is located on a second surface of the body opposite the first surface. By forming the two pressure relief grooves defining the weak portion on different surfaces of the body, it is possible to avoid the occurrence of the phenomenon of material extrusion when the two pressure relief grooves are manufactured, thereby avoiding the influence of the flatness of the surface of the body due to the material extrusion. In addition, relative to the scheme that two pressure relief grooves are arranged on the same surface, the two pressure relief grooves are formed on different surfaces of the body, so that the structural strength of the body can be further reduced, and the opening and overturning of the pressure relief portion are promoted.

In some embodiments, the first surface is an outer surface of the body and the second surface is an inner surface of the body. The first weak part for opening is arranged on the outer surface of the body, so that the first weak part can be conveniently manufactured and processed, the manufacturing quality of the first weak part is improved, and the pressure relief mechanism is promoted to accurately and effectively open a valve as required. In addition, the second pressure relief groove is arranged on the inner surface of the body, so that the pressure relief portion can be more favorably promoted to turn towards the outer part of the shell.

In some embodiments, the first relief groove has a depth greater than a depth of the second relief groove, and the first weakening is less thick than the second weakening. The scheme of the embodiment can ensure that the pressure relief part is opened at the first weak part and overturns towards one side where the second weak part is located when the internal pressure or temperature of the single battery reaches the threshold value, so that the valve opening direction of the pressure relief mechanism is ensured, and the safety of the battery is ensured.

In some embodiments, the first pressure relief groove includes a plurality of first groove portions, the plurality of first groove portions are sequentially arranged in a depth direction of the first pressure relief groove, and a width of the plurality of first groove portions gradually decreases in the depth direction of the first pressure relief groove. First pressure release groove adopts multistage groove structure, can reduce the molding force that the body received when every grade groove shaping, reduces the body and produces the risk of crackle at the in-process in the first pressure release groove of shaping, improves pressure relief mechanism's long-term reliability.

In some embodiments, the second pressure relief groove includes a plurality of second groove portions, the plurality of second groove portions are sequentially arranged in a depth direction of the second pressure relief groove, and a width of the plurality of second groove portions gradually decreases in the depth direction of the second pressure relief groove. The second pressure relief groove adopts a multi-level groove structure, so that the forming force applied to the pressure relief body during forming of each level groove can be reduced, the risk of cracks generated in the process of forming the second pressure relief groove by the pressure relief body is reduced, and the long-term reliability of the pressure relief mechanism is improved.

In some embodiments, a line connecting the two first free ends has a third projection on the plane, and the extending direction of the second projection is consistent with the extending direction of the third projection. The extending direction of the connecting line of the two free ends of the first weak portion is set to be consistent with the extending direction of the second weak portion, so that the overturning direction of the pressure relief portion can be more accurate, and the single battery is quickly and effectively relieved.

In some embodiments, the second projection at least partially overlaps the third projection in a direction perpendicular to the direction of extension of the second projection. The scheme of the embodiment can further enable the pressure relief part to turn over more quickly towards the side where the second weak part is located, so that quick and effective pressure relief of the battery cell is promoted.

In some embodiments, the second projection is located on a side of the third projection adjacent to the first projection and spaced apart from the third projection. The second weak part is arranged in the pressure relief part defined by the first weak part, so that the overturning force can be transmitted to the position near the second weak part more quickly, the overturning speed of the pressure relief part is higher, and the single battery is quickly and effectively decompressed.

In some embodiments, the second projection is located on a side of the third projection facing away from the first projection and is spaced apart from the third projection. The second weak portion is arranged on the outer side of the pressure relief portion of the first weak portion interface, so that the valve opening area of the pressure relief portion can be larger, and the single battery is quickly and effectively relieved.

In some embodiments, the perpendicular bisector of the third projection coincides with the perpendicular bisector of the second projection. According to the scheme of the embodiment, the second weak part is symmetrical relative to the perpendicular bisector of the connecting line of the two ends of the first weak part, the pressure relief part can be turned towards one side where the second weak part is located better, the turning direction and the valve opening direction of the pressure relief part are more accurate, and the safety is higher.

In some embodiments, the first projection is symmetrical with respect to a mid-normal of the third projection. According to the scheme of the embodiment, the structural strength of the first weak part on two sides of the perpendicular bisector of the first weak part is consistent, the stress bearing capacity is consistent, and the two sides of the first weak part are synchronously opened when the internal pressure of the battery cell reaches the threshold value, so that the valve opening direction of the pressure relief mechanism is more accurate, and the safety is higher.

In some embodiments, the second projection has two second free ends, and a minimum gap between one of the second free ends and the first projection is no greater than one third of the length of the third projection, and/or a minimum gap between the other of the second free ends and the first projection is no greater than one third of the length of the third projection. The above-mentioned embodiment scheme is through setting up the clearance with first weak part and second weak part in reasonable within range, can ensure that the relief portion splits back along first weak part and turns over towards the one side at second weak part place fast and accurately.

In some embodiments, the minimum gap between one of the second free ends and the first projection is less than 10mm, and/or the minimum gap between the other second free end and the first projection is less than 10mm. According to the scheme of the embodiment, the pressure relief portion can be quickly and accurately turned towards one side where the second weak portion is located, so that the pressure relief mechanism is quickly and effectively relieved.

In some embodiments, the first projection is an arc, a dogleg, or a combination of an arc and a dogleg. Through setting up first weak point into the combination of arc, broken line or pitch arc and broken line to inject the shape of relief pressure portion as required, with increase pressure release mechanism's open valve area, quick pressure release further improves the security.

In some embodiments, the casing includes a casing body having an opening and an end cap covering the opening, a receiving cavity for receiving the battery cell is formed between the casing body and the end cap, and a pressure relief mechanism is disposed on at least one side wall of the casing body and/or a pressure relief mechanism is disposed on the end cap. Can make pressure release mechanism integration on can holding the free casing of battery or end cover like this to make pressure release mechanism collection hold function and pressure release function as an organic whole.

In some embodiments, a groove is formed on the housing, and the body of the pressure relief mechanism is a groove bottom of the groove. In the above technical solution, the thickness of the bottom wall of the groove can be made smaller than the wall thickness of the other part of the housing. At this time, the bottom wall of the groove having a small thickness is used as the body of the relief mechanism, which can facilitate the opening of the relief mechanism. And the groove is formed by being sunken from the surface of the shell, so that the pressure relief mechanism can be far away from the surface of the shell, and the pressure relief mechanism is not easy to contact other objects to cause damage.

In some embodiments, the side walls of the recess comprise opposing first and second side walls, the projection of the first side wall onto the plane extends in a direction that coincides with the direction that the first projection extends, and the projection of the second side wall onto the plane extends in a direction that coincides with the direction that the second projection extends. According to the scheme of the embodiment, the weak part can be machined by taking the corresponding side wall of the groove as a reference, so that the machining of the weak part is facilitated.

In some embodiments, the thickness of the body is less than the thickness of the portion of the housing other than the pressure relief mechanism. The embodiment scheme can promote the opening and the overturning of the pressure relief part and avoid the situation that other parts of the shell are cracked in advance when the internal pressure or the temperature of the battery cell exceeds the threshold value.

Embodiments of the second aspect of the present application provide a battery cell including the housing in the above embodiments.

Embodiments of the third aspect of the present application provide a battery including the battery cell of the above embodiments.

An embodiment of a fourth aspect of the present application provides an electric device, which includes the battery in the above embodiments, and the battery is used for providing electric energy.

The technical effects of the battery cell, the battery and the power consumption device are the same as those of the housing in the above embodiments, and are not described herein again.

The above description is only an overview of the technical solutions of the present application, and the present application may be implemented in accordance with the content of the description so as to make the technical means of the present application more clearly understood, and the detailed description of the present application will be given below in order to make the above and other objects, features, and advantages of the present application more clearly understood.

Drawings

In the drawings, like reference numerals refer to the same or similar parts or elements throughout the several views unless otherwise specified. The figures are not necessarily to scale. It is appreciated that these drawings depict only some embodiments in accordance with the disclosure and are therefore not to be considered limiting of its scope.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application.

Fig. 2 is an exploded view of a battery according to some embodiments of the present disclosure.

Fig. 3 is an exploded view of a battery cell according to some embodiments of the present disclosure.

Fig. 4 is a schematic view of a battery cell according to other embodiments of the present application.

Fig. 5 is a partial enlarged view of an end cap portion of the battery cell of fig. 4.

Fig. 6 is a schematic view of an end cap of the cell of fig. 4.

Fig. 7 is another schematic view of an end cap of the cell of fig. 4.

Fig. 8 is another schematic view of an end cap of the cell of fig. 4.

Fig. 9 is a cross-sectional view of the end cap of fig. 8.

Fig. 10 is an enlarged partial view of the relief mechanism portion of the endcap of fig. 9.

FIG. 11 is a schematic view of a first weakness according to some embodiments of the present application.

FIG. 12 is a schematic view of a second weakened portion according to some embodiments of the present application.

FIG. 13 is a schematic view of an end cap including a pressure relief mechanism according to other embodiments of the present application.

FIG. 14 is a schematic illustration of an endcap including a pressure relief mechanism according to further embodiments of the present application.

FIG. 15 is a schematic view of an end cap including a pressure relief mechanism according to other embodiments of the present application.

Description of reference numerals:

a vehicle 1000;

battery 100, controller 200, motor 300;

a box body 10, a first part 11, a second part 12;

the battery cell 20, the end cover 21, the electrode terminal 21a, the shell 22, the electric core assembly 23 and the tab 23a;

the pressure relief mechanism 430 includes a housing 40, a case 410, an end cap 420, a pressure relief mechanism 430, a body 431, a first weak portion 432, first free ends 432a and 432b, a pressure relief portion 4311, a second weak portion 433, a first direction z, a plane P, a first projection 4321, a second projection 4331, a third projection 4323, a first pressure relief groove 4322, a second pressure relief groove 4332, a first groove 4322a, a second groove 4332a, second free ends 4331a and 4331b, through holes 421 and 422, a first side wall 441, and a second side wall 442.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present application more clearly, and therefore are only used as examples, and the protection scope of the present application is not limited thereby.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or to implicitly indicate the number, specific order, or primary-secondary relationship of the technical features indicated. The meaning of "a plurality" in the description of the embodiments of the present application is two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two sets), "plural pieces" refers to two or more (including two pieces).

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate orientations or positional relationships that are based on the orientations or positional relationships shown in the drawings, merely for convenience of description and simplification of the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

At present, the application of the power battery is more and more extensive from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles and electric automobiles, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

For the battery cell, the main safety hazard comes from the charging and discharging process, together with a suitable ambient temperature. In order to effectively avoid unnecessary losses, at least three protective measures are generally taken for the battery cells. In particular, the protective measures comprise at least a switching element, selection of a suitable isolating membrane material and a pressure relief mechanism. The switching element is an element that can stop charging or discharging the battery when the temperature or resistance in the battery cell reaches a certain threshold value. The isolating membrane is used for isolating the positive pole piece and the negative pole piece, and can automatically dissolve the micron-scale (even nano-scale) micropores attached to the anode piece when the temperature rises to a certain value, so that metal ions cannot pass through the isolating membrane, and the internal reaction of the battery monomer is stopped.

The pressure relief mechanism refers to an element or a component that is activated to relieve the internal pressure or temperature of the battery cell when the internal pressure or temperature reaches a predetermined threshold. The threshold design varies according to design requirements. The threshold value may depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte and the separator in the battery cell. As used herein, "activate" means that the pressure relief mechanism is activated or activated to a certain state, such that the internal pressure and temperature of the battery cell are relieved. The actions generated by the pressure relief mechanism may include, but are not limited to: at least a portion of the pressure relief mechanism ruptures, fractures, is torn or opened, or the like. When the pressure relief mechanism is actuated, high-temperature and high-pressure substances inside the battery cell are discharged outwards from the actuated part as emissions. In this way, the cells can be vented under controlled pressure or temperature, thereby avoiding potentially more serious accidents. Reference herein to emissions from a battery cell includes, but is not limited to: electrolyte, dissolved or split anode and cathode pole pieces, fragments of a separation film, high-temperature and high-pressure gas generated by reaction, flame and the like.

The pressure relief mechanism on the battery cell has an important influence on the safety of the battery. For example, when a short circuit, overcharge, or the like occurs, thermal runaway may occur inside the battery cell, and the pressure or temperature may suddenly rise. In this case, the internal pressure and temperature can be released outwards by the actuation of the pressure relief mechanism, so that the battery cells are prevented from exploding and firing. The pressure relief mechanism may take the form of, for example, an explosion-proof valve, a gas valve, a pressure relief valve, or a safety valve, and may specifically employ a pressure-sensitive or temperature-sensitive element or configuration, that is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the pressure relief mechanism performs an action or a weak structure provided in the pressure relief mechanism is broken, thereby forming a through-hole or a passage through which the internal pressure or temperature can be relieved.

The inventor notices that for a general pressure relief mechanism, the whole explosion-proof valve is easily and completely broken and forms a plurality of fragments separated from the top cover plate, and the fragments easily cause damage to other parts and affect the safety of the power battery. In addition, after the single battery is used for a period of time, the pressure relief mechanism is easy to relieve pressure or crack in an unexpected place when the internal pressure of the single battery does not reach the detonation pressure, so that the single battery is opened abnormally, even the whole single battery fails, and the service life and the safety of the single battery are influenced.

In view of this, the present embodiments provide a housing for a battery cell, including a pressure relief mechanism. The pressure relief mechanism includes a body, a first weakened portion and a second weakened portion. The first weak portion is arranged on the body and provided with two first free ends, and a connecting line of the two first free ends is not completely overlapped with the first weak portion and defines a pressure relief portion together. The second weak portion is arranged on the body, and a first projection of the second weak portion on a plane perpendicular to the first direction does not intersect with a second projection of the second weak portion on the plane, and the first direction is the thickness direction of the pressure relief portion. The pressure relief portion is configured to open and flip toward a side where the second weak portion is located, with the first weak portion as a boundary, when a pressure or a temperature inside the battery cell reaches a threshold value.

Through setting up first weak part and second weak part in pressure release mechanism for when pressure or the temperature of battery monomer inside reach the threshold value, the pressure release portion opens and overturns towards one side at second weak part place along first weak part. The extending direction of the first weak portion defines a valve opening direction of the pressure relief mechanism so that countermeasures are taken in advance, thereby improving the safety of the battery. The setting of second weak part can make the speed of relief pressure portion upset faster to promote the relief pressure portion upset after splitting with quick pressure release, avoid it to be broken away completely and form a plurality of fragments.

In addition, in the above technical scheme, the projections of the first weak portion and the second weak portion on the plane perpendicular to the first direction do not intersect, so that stress concentration of the weak portions in the intersecting region can be avoided, the risk that the pressure relief mechanism starts to relieve pressure when the pressure inside the single battery does not reach the initiation pressure is reduced, the risk that the pressure relief mechanism cracks in the intersecting region to cause a valve opening direction error is avoided, the breakage resistance of the pressure relief mechanism is improved, effective pressure relief of the single battery is promoted, and the service life of the single battery is prolonged.

The housing disclosed in the embodiments of the present application may be, but is not limited to, used for a battery cell. The battery cell may include a lithium ion battery, a secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiments of the present application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application.

The battery cell disclosed in the embodiment of the present application can be used in, but not limited to, an electric device for a vehicle, a ship, an aircraft, or the like. A power supply system including the electric device composed of the battery cell, the battery, and the like disclosed in the present application may be used.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

For convenience of description, the following embodiments are described by taking an electric device according to an embodiment of the present application as an example of a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or an extended range automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, and for example, the battery 100 may serve as an operation power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide a receiving space for the battery cells 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 cover each other, and the first portion 11 and the second portion 12 together define a receiving space for receiving the battery cell 20. The second part 12 may be a hollow structure with an open end, the first part 11 may be a plate-shaped structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a containing space; the first portion 11 and the second portion 12 may be both hollow structures with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the case 10 formed by the first and second portions 11 and 12 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the number of the battery cells 20 may be multiple, and the multiple battery cells 20 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the multiple battery cells 20. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and the whole is accommodated in the box 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3, fig. 3 is an exploded structural schematic diagram of a battery cell 20 according to some embodiments of the present disclosure. The battery cell 20 refers to the smallest unit constituting the battery. Referring to fig. 3, the battery cell 20 includes an end cap 21, a housing 22, a battery cell assembly 23, and other functional components.

The end cap 21 refers to a member that covers an opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 21 is not easily deformed when being impacted, and the battery cell 20 may have a higher structural strength and improved safety. The end cap 21 may be provided with functional components such as the electrode terminals 21 a. The electrode terminal 21a may be used to electrically connect with the electric core assembly 23 for outputting or inputting the electric power of the battery cell 20. In some embodiments, the end cap 21 may further include a pressure relief mechanism for relieving the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a threshold value. The material of the end cap 21 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present invention is not limited thereto. In some embodiments, insulation may also be provided on the inside of the end cap 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of shorting. Illustratively, the insulator may be plastic, rubber, or the like.

The housing 22 is an assembly for mating with the end cap 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to house the cell assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 may be separate components, and an opening may be provided in the housing 22, and the opening may be covered by the end cap 21 to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 may be integrated, and specifically, the end cap 21 and the housing 22 may form a common connecting surface before other components are inserted into the housing, and when it is necessary to enclose the inside of the housing 22, the end cap 21 covers the housing 22. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 may be determined according to the specific shape and size of the electric core assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in the embodiments of the present invention.

The cell assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrical core assemblies 23 may be contained within the housing 22. The core assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative plates having the active material constitute a main body portion of the core assembly, and the portions of the positive and negative plates having no active material each constitute a tab 23a. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charge and discharge of the battery, the positive and negative active materials react with the electrolyte, and the tab 23a is connected to the electrode terminal to form a current loop.

According to some embodiments of the present application, as shown in fig. 4-8, the present application provides a housing 40 for a battery cell including a pressure relief mechanism 430. The pressure relief mechanism 430 includes a body 431, a first weak portion 432, and a second weak portion 433. The first weak portion 432 is disposed on the body 431 and has two first free ends 432a, 432b, and a connection line of the two first free ends 432a, 432b does not completely overlap with the first weak portion 432 and defines a pressure relief portion 4311 together. The second weak portion 433 is provided to the body 431, and a first projection 4321 of the second weak portion 433 on a plane perpendicular to a first direction z, which is a thickness direction of the pressure relief portion 4311, and a second projection 4331 of the second weak portion 433 on the plane do not intersect. The pressure relief portion 4311 is configured to open and turn toward the side where the second weak portion 433 is located with the first weak portion 432 as a boundary when the pressure or temperature inside the battery cell reaches a threshold value.

The battery cell in the above embodiment has substantially the same features as the battery cell 20 described above in fig. 2 and 3, and will not be described in detail. The housing 40 may include an end cap 420 and a shell 410. Here, the features of the end cap 420 and the housing 410 are substantially the same as those of the end cap 21 and the housing 22 described above in fig. 3, and are not described in detail. The body 431 of the pressure relief mechanism 430 may be a separate component mounted on the case 410 or the cap 420, for example, the body 431 may be a plate-shaped structure, specifically, a rupture disk, mounted on the cap 420 or the case 410. For another example, the body 431 may be integrally formed with the end cap 420 or the housing 410, i.e., a portion of the end cap 420 or the housing 410 itself is the body 431.

The first weak portion 432 and the second weak portion 433 may be portions of the body 431 having a small thickness or portions of the body 431 having a low material strength, and the present application is not limited to the above examples. The first weak portion 432 serves to define a preferential breaking position of the pressure relief mechanism 430, and the pressure relief mechanism 430 is preferentially ruptured from the first weak portion 432 when the internal pressure or temperature of the battery cell reaches a threshold value. When the internal pressure or temperature of the battery cell reaches a threshold value, the pressure relief mechanism 430 is ruptured from the first weak portion 432 and then turned over toward the side where the second weak portion 433 is located.

As shown in fig. 7, the first direction z is a thickness direction of the pressure relief portion 3411. At this time, the first direction z is also the thickness direction of the end cap 420. Alternatively, when the pressure relief mechanism 430 is provided on the case 410, the first direction z is also a thickness direction of a corresponding wall of the case 410. Further, the thickness direction of the first weak portion 432 and the second weak portion 433 is along the first direction z, i.e., the thickness direction of the pressure relief portion 3411.

The plane perpendicular to the first direction z may be a surface of the body 431 facing the inside of the battery cell, such as a plane P shown in fig. 8, a surface of the body 431 facing away from the inside of the battery cell, or any plane perpendicular to the first direction z. The first projection 4321 of the first weak portion 432 on a plane perpendicular to the first direction z and the second projection 4331 of the second weak portion 433 on the same plane do not intersect, which means that the first projection 4321 and the second projection 4331 are not connected together, a gap exists between one end of the second projection 4331 close to the first projection 4321 and the first projection 4321, and there is no overlapping portion of the first projection 4321 and the second projection 4331. The first weak portion 432 and the second weak portion 433 may be formed on the same surface of the case 40, or may be formed on both surfaces of the case 40 opposite to each other. When the first and second weak portions 432 and 433 are formed on the same surface, the first and second projections 4321 and 4331 do not intersect may mean that the first and second weak portions 432 and 433 are not connected together, a gap exists between one end of the second weak portion 433 close to the first weak portion 432 and the first weak portion 432, and there is no overlapping portion of the first and second weak portions 432 and 433.

The line connecting the two first free ends 432a and 432b of the first weak portion 432 and the first weak portion 432 do not completely overlap with each other, which means that the first weak portion 432 does not extend in a straight line, and is bent during the extending process, that is, the line connecting the first weak portion 432 and the two first free ends 432a and 432b may enclose an area.

The pressure relief portion 4311 is an area of the body 431 defined by the first weakened portion 432 and the two first free ends 432a, 432b thereof in common. When the internal pressure or temperature of the battery cell reaches a threshold value, the pressure relief portion 4311 will preferentially split from the first weak portion 432, thereby partially separating from the body 431. Then, the pressure relief portion 4311 may be turned over toward the side where the second weak portion 433 is located by the impact of the internal discharge of the battery cell, etc., so that the pressure relief portion 4311 is opened outward. After the pressure relief portion 4311 is opened, the body 431 forms a pressure relief opening at a position corresponding to the pressure relief portion 4311, through which the emissions (gas, electrolyte, etc.) inside the battery cell can be discharged to release the pressure inside the battery cell.

The case in fig. 4 and 5 has a cylindrical shape, but the case for the battery cell is not limited to a cylindrical shape, and may have, for example, a rectangular parallelepiped shape or a hexagonal prism shape.

In the above embodiment, the first weak portion for rupturing when the internal pressure or temperature of the battery cell exceeds the threshold value may define the valve opening direction of the pressure relief mechanism 430, so that a countermeasure may be taken in advance, thereby improving the battery safety. The second weak portion 433 may make the pressure relief portion 4311 turn faster, thereby promoting rapid and effective pressure relief of the battery cell. In addition, the projections of the first weak portion 432 and the second weak portion 433 on a plane perpendicular to the first direction do not intersect, so that stress concentration of the weak portions in an intersecting region can be avoided, the risk that the pressure relief mechanism 430 starts pressure relief when the pressure inside the battery cell does not reach the detonation pressure is reduced, the condition that the valve opening direction is wrong due to rupture of the pressure relief mechanism in the intersecting region is avoided, the anti-damage capability of the pressure relief mechanism 430 is improved, effective pressure relief of the battery cell is promoted, and the service life of the battery cell is prolonged.

According to some embodiments of the present application, as shown in fig. 9 and 10, the body 431 is formed with a first relief groove 4322 and a second relief groove 4332, the first weak portion 432 is a bottom wall of the first relief groove 4322, and the second weak portion 433 is a bottom wall of the second relief groove 4332.

The first relief groove 4322 is formed by a surface of the outer shell 40 (e.g., the end cap 420 or the case 410) being recessed in the thickness direction, i.e., the first direction z. The first relief groove 4322 reduces the thickness of the wall of the housing 40, thereby forming the first weakened portion 432. First vent groove 4322 may be a score provided on a surface of body 431, may be formed by machining body 431, or may be integrally formed with shell 40 (e.g., end cap 420 or housing 410). The processing manner for forming the first pressure relief groove 4322 may include carving, stamping, milling, and the like, and the application is not limited thereto.

The second relief groove 4332 is formed by a surface of the housing 40 (e.g., the end cap 420 or the case 410) being recessed in the thickness direction, i.e., the first direction z. The second relief groove 4332 reduces the thickness of the wall of the housing 40, thereby forming the second weak portion 433. Second vent groove 4332 may be a score provided on a surface of body 431, may be formed by machining body 431, or may be integrally formed with shell 40 (e.g., end cap 420 or housing 410). The processing manner for forming the second pressure relief groove 4332 may include carving, stamping, milling, and the like, and the application is not limited thereto.

The first and second vent grooves 4322, 4332 may be formed on the same surface of the outer shell 40 (e.g., the end cap 420 or the housing 410), or on surfaces of the outer shell 40 that are opposite to each other.

The weak portion is provided as the bottom of the pressure relief groove to form a weak position of the pressure relief mechanism 430, which may facilitate the manufacturing process of the weak portion.

According to some embodiments of the present application, as shown in fig. 9 and 10, the first pressure relief groove 4322 is located at a first surface of the body 431, and the second pressure relief groove 4332 is located at a second surface of the body 431 opposite to the first surface.

That is, the first pressure relief groove 4322 and the second pressure relief groove 4332 are respectively located on two surfaces of the body 431 opposite to each other. For example, when the pressure relief mechanism 430 is disposed on the end cap 420, the first pressure relief groove 4322 may be located on a surface of the end cap 420 facing away from the interior of the cell, and the second pressure relief groove 4332 may be located on a surface of the end cap 420 facing toward the interior of the cell. Alternatively, the first pressure relief groove 4322 may also be located on the surface of the end cap 420 facing the interior of the cell, and the second pressure relief groove 4332 may be located on the surface of the end cap 420 facing away from the interior of the cell. For another example, when the pressure relief mechanism 430 is disposed on the housing 410, the first pressure relief groove 4322 may be located on a surface of a wall of the housing 410 facing away from the interior of the battery cell, and the second pressure relief groove 4332 may be located on a surface of the same wall of the housing 410 facing toward the interior of the battery cell. Alternatively, the first pressure relief groove 4322 may be located on a surface of a wall of the housing 410 facing the inside of the battery cell, and the second pressure relief groove 4332 may be located on a surface of the same wall of the housing 410 facing away from the inside of the battery cell.

Optionally, a second pressure relief groove 4332 is formed on the inner surface of the body 431 to facilitate the quick turning of the pressure relief portion toward the outside of the housing.

The above embodiment scheme can avoid the extrusion phenomenon when two pressure relief grooves are manufactured by forming the two pressure relief grooves for limiting the weak part on different surfaces of the body, thereby avoiding the influence of the flatness of the surface of the body caused by extrusion. In addition, for the scheme that two pressure relief grooves are arranged on the same surface, the structural strength of the body can be further reduced by forming the two pressure relief grooves on different surfaces of the body, so that the opening and overturning of the pressure relief portion are promoted.

According to some embodiments of the present application, as shown in fig. 9 and 10, the first surface is an outer surface of the body 431 and the second surface is an inner surface of the body 431.

The outer surface of the body 431 is the surface of the body 431 facing away from the interior of the cell. An inner surface of the body 431 is a surface of the body 431 facing the inside of the battery cell. That is, the first pressure relief groove 4322 may be located on a surface of the housing 40 (e.g., the housing 410 or the end cap 420) facing away from the interior of the cell, while the second pressure relief groove 4332 may be located on a surface of the housing 40 facing toward the interior of the cell.

The above embodiment may facilitate the manufacturing process of the first pressure relief groove 4322 by disposing the first weak portion 432 for opening on the outer surface of the body 431, improve the manufacturing quality of the first weak portion 432, and thus facilitate the pressure relief mechanism 430 to open the valve accurately and effectively as required. Further, providing the second relief groove 4332 on the inner surface of the body 431 is more advantageous in facilitating the turning of the relief portion 4311 toward the outside of the housing.

According to some embodiments of the present application, the depth of the first relief groove 4322 is greater than the depth of the second relief groove 4332, and the thickness of the first weak portion 432 is less than the thickness of the second weak portion 431.

The depth of the first relief groove 4322 being greater than the depth of the second relief groove 4332 may allow the thickness of the body 431 at the first relief groove 4322 to be thinner. In the case where the thickness of the body 431 is the same, the thickness of the first weak portion 432 formed on the bottom wall of the first relief groove 4322 may be made smaller than the thickness of the second weak portion 433 formed on the bottom wall of the second relief groove 4332.

The embodiment scheme can enable the structural strength of the body 431 at the first weak portion 432 to be lower than that of the second weak portion 433, so that the pressure relief portion 4311 preferentially cracks at the first weak portion and turns towards the side where the second weak portion 433 is located when the internal pressure or temperature of the single battery reaches a threshold value, and therefore the accurate valve opening direction of the pressure relief mechanism is ensured, and the safety of the battery is ensured.

According to some embodiments of the present application, as shown in fig. 11, the first pressure relief groove 4322 includes a plurality of first groove portions 4322a, the plurality of first groove portions 4322a are sequentially arranged along a depth direction of the first pressure relief groove 4322, and a width of the plurality of first groove portions 4322a is gradually reduced along the depth direction of the first pressure relief groove 4322.

Each of the first groove parts 4322a in the first pressure relief groove 4322 extends in the same direction. The depth of each first groove portion 4322a may be equal or different, for example, the depth of each first groove portion 4322a gradually decreases along the depth direction (i.e., the first direction z) of the first relief groove 4322.

The number of the first groove portions 4322a in the first pressure relief groove 4322 may be two, three, four, or more. Illustratively, in fig. 11, there are three first groove portions 4322a in the first relief groove 4322. The following describes the processing manner of the first pressure relief groove 4322 by taking the first pressure relief groove 4322 as an example and forming the first pressure relief groove 4322 by stamping: first groove 4322a may be punched on the surface of the body 431, and then second first groove 4322a may be punched on the bottom surface of the first groove 4322a, and finally third first groove 4322a may be punched on the bottom surface of the second first groove 4322a. It can be appreciated that the width of the first slot portion 4322a can be greater than the width of the second first slot portion 4322a, and the width of the second first slot portion 4322a can be greater than the width of the third first slot portion 4322a.

The first pressure relief groove 4322 has a multi-stage groove structure, so that the molding force applied to the body 431 during molding of each stage groove can be reduced, the risk of cracks generated in the process of molding the first pressure relief groove 4322 by the body 431 is reduced, and the long-term reliability of the pressure relief mechanism 430 is improved.

According to some embodiments of the present application, as shown in fig. 12, the second pressure relief groove 4332 includes a plurality of second groove portions 4332a, the plurality of second groove portions 4332a are sequentially arranged along a depth direction of the second pressure relief groove 4332, and a width of the plurality of second groove portions 4332a is gradually reduced along the depth direction of the second pressure relief groove 4332.

Each of the second groove portions 4332a in the second pressure relief groove 4332 extends in the same direction. The depths of the second groove portions 4332a may be equal or different, for example, the depths of the second groove portions 4332a gradually decrease in the depth direction (i.e., the first direction z) of the second relief grooves 4332.

The number of the second groove portions 4332a in the second pressure relief groove 4332 may be two, three, four, or more. Illustratively, in fig. 12, there are three second groove portions 4332a in the second relief groove 4332. The second pressure relief groove 4332 is formed in the same manner as the first pressure relief groove, and is not described herein again.

The second pressure relief groove 4332 has a multi-stage groove structure, so that the molding force applied to the body 431 during molding of each stage groove can be reduced, the risk of cracks generated in the process of molding the second pressure relief groove 4332 by the body 431 is reduced, and the long-term reliability of the pressure relief mechanism 430 is improved.

According to some embodiments of the present application, as shown in fig. 13, a line connecting the two first free ends 432a, 432b has a third projection 4323 on a plane, and an extending direction of the second projection 4331 is identical to an extending direction of the third projection 4323.

As described above, the plane is a plane perpendicular to the first direction z, and may be a surface of the body 431 facing the inside of the battery cell, such as a plane P shown in fig. 8, a surface of the body 431 facing away from the inside of the battery cell, or any plane perpendicular to the first direction z. The extension direction of the second projection 4331 and the extension direction of the third projection 4323 may be the same, and the second projection 4331 and the third projection 4323 may be parallel (i.e. there is a gap in a direction perpendicular to the extension direction) and the second projection 4331 and the third projection 4323 are in a straight line (including complete coincidence, partial coincidence or non-coincidence). The parallelism between the second projection 4331 and the third projection 4323 may include parallelism in a case where the perpendicular bisectors of the second projection 4331 and the third projection 4323 coincide with each other, the perpendicular bisectors of the second projection 4331 and the third projection 4323 do not coincide with each other, and the second projection 4331 and the third projection 4323 at least partially face each other, or the perpendicular bisectors of the second projection 4331 and the third projection 4323 do not coincide with each other, and the second projection 4331 and the third projection 4323 do not face each other at all (i.e., are completely deviated from each other), and the present application is not limited to the above examples. It should be noted here that the "extending directions coincide" as referred to herein may mean that the extending directions of the two projections are 0 ° or 180 °, or that the extending directions of the two projections are approximately 0 ° or 180 °.

The above embodiment may make the turning direction of the pressure relief portion 4311 more accurate by setting the extending direction of the connecting line of the two free ends 432a, 432b of the first weak portion 432 to be identical to the extending direction of the second weak portion 433, thereby promoting effective pressure relief of the battery cell.

According to some embodiments of the present application, as illustrated in fig. 8, 13 and 14, the second projection 4331 at least partially overlaps the third projection 4323 in a direction perpendicular to the direction of extension of the second projection 4331.

In particular, the second projection 4331 at least partially opposes the third projection 4323 if the second projection 4331 is parallel to the third projection 4323, or the second projection 4331 at least partially overlaps the third projection 4323 if the second projection 4331 and the third projection 4323 are in a straight line. In the case that the second projection 4331 is parallel to the third projection 4323, the second projection 4331 and the third projection 4323 at least partially opposite may include the case that the midperpendicular of the second projection 4331 and the third projection 4323 coincides, and the case that the midperpendicular of the second projection 4331 and the third projection 4323 does not coincide and the second projection 4331 and the third projection 4323 at least partially opposite. In the case where the second projection 4331 is in line with the third projection 4323, the at least partial overlap of the second projection 4331 with the third projection 4323 may include the second projection 4331 being completely coincident with the third projection 4323 (including the shorter projection being completely within the longer projection or the same two projections being completely coincident), or the second projection 4331 being partially coincident with the third projection 4323.

The above embodiment scheme can further make the pressure relief portion 4311 turn over faster toward the side where the second weak portion is located, thereby promoting quick and effective pressure relief of the battery cell.

According to some embodiments of the present application, as shown in fig. 13, the second projection 4331 is located on a side of the third projection 4323 close to the first projection 4321 and is spaced apart from the third projection 4323.

That is, the second projection 4331 is located in the relief portion 4311 defined by the connection line of the first weak portion 432 and the two first free ends 432a and 432b thereof, and is close to the third projection 4323.

The scheme of the embodiment can enable the overturning force to be transmitted to the position near the second weak portion more quickly, so that the overturning speed of the pressure relief portion is higher, and quick and effective pressure relief of the battery cell is realized.

According to some embodiments of the present application, as shown in fig. 14, the second projection 4331 is located on a side of the third projection 4323 facing away from the first projection 4321 and is spaced apart from the third projection 4323.

That is, as shown in fig. 14, the second projection 4331 is located outside the pressure relief portion 4311 defined by the connection line between the first weakened portion 432 and the two first free ends 432a and 432b thereof, and is close to the third projection 4323.

The embodiment scheme can enable the valve opening area of the pressure relief portion to be larger, and therefore rapid and effective pressure relief of the battery cells is promoted.

According to some embodiments of the present application, as shown in fig. 8, 13, and 14, the perpendicular bisector of the third projection 4323 coincides with the perpendicular bisector of the second projection 4331.

Specifically, as shown in fig. 8, when the third projection 4323 and the second projection 4331 are located on the same straight line, the third projection 4323 and the second projection 4331 are completely overlapped and symmetrical along the perpendicular bisector; as shown in fig. 13 and 14, when the third projection 4323 is parallel to the second projection 4331, the third projection 4323 is completely opposite to the second projection 4331 and is symmetrical along the perpendicular bisector.

The above embodiment can realize that the second weak portion 433 is symmetrical with respect to the perpendicular bisector of the two first free ends 432a, 432b of the first weak portion 432, so that the relief portion 4311 is turned toward the side where the second weak portion is located better, the turning direction and the valve opening direction of the relief portion are more accurate, and the safety is higher.

According to some embodiments of the present application, as shown in fig. 8, 13, and 14, the first projection 4321 is symmetrical with respect to a mid-vertical line of the third projection 4323.

That is, the first weakened portion 432 is symmetrical with respect to a perpendicular bisector of a line connecting the two first free ends 432a, 432b thereof.

The scheme of the embodiment can realize that the structural strength of the first weak part 432 on two sides of the perpendicular line is consistent, the stress bearing capacity is consistent, and the two sides of the first weak part 432 are synchronously opened when the internal pressure of the battery cell reaches a threshold value, so that the valve opening direction of the pressure relief mechanism 430 is more accurate, and the safety is higher.

According to some embodiments of the present application, as shown in fig. 14, the second projection 4331 has two second free ends 4331a, 4331b, and a minimum gap M1 between one of the second free ends 4331a and the first projection 4321 is not more than one third of the length L of the third projection 4323, and/or a minimum gap M2 between the other second free end 4331b and the first projection 4321 is not more than one third of the length L of the third projection 4323.

The minimum gap M1 between the second free end 4331a and the first projection 4321 is the perpendicular distance from the second free end 4331a to the first projection 4321. The minimum gap M2 between the second free end 4331b and the first projection is the perpendicular distance from the second free end 4331b to the first projection 4321.

The above embodiment scheme can ensure that the pressure relief portion is quickly and accurately turned towards the side where the second weak portion 433 is located after the first weak portion 432 is split by setting the gap between the first weak portion 432 and the second weak portion 433 within a reasonable range.

According to some embodiments of the present application, as shown in fig. 14, a minimum gap M1 between one of the second free ends 4331a and the first projection 4321 is less than 10mm, and/or a minimum gap M2 between the other second free end 4331b and the first projection 4321 is less than 10mm.

That is, the distance between the second weak portion 433 and the first weak portion 432 in the vertical direction and the first direction z may not be too large, and the too large distance may make the second weak portion 433 unable to play an effect of increasing the turning speed of the pressure relief portion 4311.

The above embodiment can promote the pressure relief portion 4311 to be quickly and accurately turned towards the side where the second weak portion 433 is located, thereby promoting the pressure relief mechanism 430 to quickly and effectively relieve pressure.

According to some embodiments of the present application, the first projection 4321 is arc-shaped, dog-leg shaped, or a combination of arc-shaped and dog-leg shaped.

That is, the first weak portion 432 extends along a trajectory of an arc, a fold line, or a combination of the arc and the fold line.

In the embodiment, by setting the shape of the extending locus of the first weak portion 432, the shape of the pressure relief portion 4311 can be set, so that the valve opening area of the pressure relief mechanism 430 is increased, the pressure is quickly relieved, and the safety is further improved. In the case where the length and width of the relief portion 4311 defined by the first weak portion 432 are constant, the valve-opening area defined by the arc shape is larger than the valve-opening area defined by the fold line shape, and thus the safety can be further improved. In addition, in the case where the valve opening area is constant, the line connecting the two first free ends of the arc-shaped first weak portion 432 is shorter, thereby having less influence on the structural strength of the housing 40.

According to some embodiments of the present application, the second projection 4331 (i.e., the second weakened portion 433) may be linear, i.e., extend along a linear trajectory, thereby facilitating the flipping of the vent portion 4311.

According to some embodiments of the present application, the housing 40 includes a case 410 having an opening and an end cap 420 covering the opening, a receiving cavity for receiving the battery cell is formed between the case 410 and the end cap 420, and a pressure relief mechanism 430 is disposed on at least one side wall of the case 410 and/or a pressure relief mechanism 430 is disposed on the end cap 420.

The battery cell in the above embodiment has substantially the same features as the battery cell 20 described in fig. 2 and 3, and will not be described in detail. The features of the end cap 420 and the housing 410 are substantially the same as the features of the end cap 21 and the housing 22 described above in fig. 3 and will not be described in detail here. Pressure relief mechanism 430 may be provided on either housing 410 or end cap 420. It is understood that when the pressure relief mechanism 430 is disposed on the housing 410, the pressure relief mechanism 430 may be disposed on only one wall, or the pressure relief mechanism 430 may be disposed on multiple walls. Further, multiple pressure relief mechanisms 430 may be included in the housing 40, and the multiple pressure relief mechanisms 430 may be disposed entirely on the case 410, or entirely on the endcap 420, or partially on the case 410 and partially on the endcap 420.

This allows the pressure relief mechanism 430 to be integrated into the case 410 or the cap 420 that can accommodate the battery cell, thereby integrating the accommodation function and the pressure relief function.

According to some embodiments of the present application, as shown in fig. 15, a groove 440 is formed on the housing 40, and the body 431 of the pressure relief mechanism 430 is a groove bottom of the groove 440.

The groove 440 may be provided on the end cap 420 as shown in fig. 15. Additionally or alternatively, the groove 440 may also be provided on the housing 410. In the case where the groove 440 is provided to the end cap 420, the groove 440 is formed by recessing the surface of the end cap 420 in the thickness direction. The groove 440 may be provided on the inner surface or the outer surface of the end cap 420. In the case where the groove 440 is provided to the case 410, the groove 440 is formed by an outer surface or an inner surface of the case 410 being depressed in the thickness direction. The groove 440 may be formed by cutting, punching, or the like on the housing 40, or may be integrally cast with the housing 40.

By providing the groove 440 in the housing 40 and forming the body 431 on the bottom wall of the groove 440, the thickness of the body 431 can be made smaller than the thickness of the other part of the housing 40, thereby facilitating the valve opening of the pressure release mechanism 430. In addition, the groove 440 is concavely molded from the surface of the case 40, whereby the pressure relief mechanism 430 formed on the bottom wall of the groove 440 may be distant from the surface of the case 40, so that the pressure relief mechanism 430 is not easily damaged by contact with other objects.

According to some embodiments of the present application, as shown in fig. 15, the side walls of the recess 440 include opposite first and second side walls 441, 442, a projection of the first side wall 441 onto a plane extends in a direction that coincides with an extension direction of the first projection 4321, and a projection of the second side wall 442 onto a plane extends in a direction that coincides with an extension direction of the second projection 4331.

The plane may be a surface of the body 431 facing the inside of the battery cell, such as the plane P shown in fig. 8, a surface of the body 431 facing away from the inside of the battery cell, or any plane perpendicular to the first direction z. The extension direction of the projection of the first side wall 441 on the plane and the extension direction of the first projection 4321 may be completely coincident, i.e., completely parallel, or parallel with a certain deviation. The extension direction of the projection of the second side wall 442 on the plane and the extension direction of the second projection 4331 may be completely coincident, i.e., completely parallel, or parallel with a certain deviation.

The above-described embodiment may enable the weak portion to be processed with reference to the corresponding sidewall of the groove 440, thereby facilitating the processing of the weak portion.

According to some embodiments of the present application, the thickness of the body 431 is less than the thickness of the portion of the housing 40 other than the pressure relief mechanism 430.

That is, the thickness of the portion of the housing 40 where the body 431 is located is smaller than the wall thickness of the other portion of the housing 40.

The above embodiment can promote smooth opening and turning of the pressure relief portion 4311, and avoid pre-splitting of the housing elsewhere when the internal pressure or temperature of the battery cell exceeds a threshold value.

According to some embodiments of the present application, as shown in fig. 15, the end cap 420 may further include two through holes 421, 422 for mounting the electrode terminals. At this time, when the pressure relief mechanism 430 is provided on the end cap 420, the second weak portion 433 may be parallel to a line connecting the two through holes 421, 422, and the first weak portion 432 intersects a perpendicular bisector of the line connecting the two through holes 421, 422. This is because the end cap 420 is expanded and deformed when the internal pressure of the battery cell increases, and the perpendicular bisector of the connecting line of the two through holes 421 and 422 is the stress deformation center line of the end cap 420, on which the stress of the end cap is relatively concentrated. By setting the first weak portion 432 of the pressure relief mechanism 430 to intersect with the perpendicular bisector of the connecting line of the two through holes 421 and 422, when the internal pressure of the battery cell reaches a threshold value, the first weak portion preferentially cracks at a certain position inside the first weak portion and continuously cracks towards two sides, the valve opening area is further increased, and effective pressure relief is achieved.

According to some embodiments of the present application, the thickness of the first weak portion 432 is gradually increased in a direction away from the perpendicular bisector of the line connecting the two through holes 421, 422 at one side or both sides of the perpendicular bisector of the line connecting the two through holes 421, 422. By locating the position where the thickness of the first weak portion 432 of the pressure relief mechanism 430 is the smallest on the perpendicular bisector of the line connecting the two through holes 421 and 422, it is possible to cause the maximum stress received by the cap 420 to act on the position where the thickness of the first weak portion is the smallest when the internal pressure of the battery cell reaches a threshold value, so as to ensure that the first weak portion 432 of the pressure relief mechanism 430 is preferentially ruptured at the position where the thickness is the smallest. Subsequently, under the action of the internal pressure of the battery cell, the pressure relief mechanism 430 is easy to continuously split along the first weak portion 432, and the valve opening area is further increased, so that effective pressure relief is realized, and the safety of the battery is ensured.

According to some embodiments of the present application, the first weak portion 432 is symmetrical with respect to a perpendicular bisector of a line connecting the two through holes 421, 422. Therefore, the first weak portion 432 can be stressed uniformly on two sides of the perpendicular bisector, and the pressure relief mechanism 430 is guaranteed to be split from the middle to two sides along the first weak portion 432, so that the valve opening direction of the pressure relief mechanism 430 is further controlled, and the safety is improved. Additionally, the second weak portion 433 may also be symmetrical with respect to a perpendicular bisector of a line connecting the two through holes 421, 422.

According to some embodiments of the present application, as shown in fig. 4-15, the present application provides a housing 40 for a battery cell, including a case 410 including an opening, an end cap 420 covering the opening, and a pressure relief mechanism 430. The pressure relief mechanism 430 includes a body 431, a first weak portion 432, and a second weak portion 433. The cap 420 has a groove 440 formed therein, and the body 431 of the pressure relief mechanism 430 is a bottom of the groove 440. The first weak portion 432 is disposed on the body 431 and has two first free ends 432a and 432b, and a connecting line of the two first free ends 432a and 432b and the first weak portion 432 together define a pressure relief portion 4311. The first weakened portion 432 extends along an arcuate path. The second weak portion 433 is disposed on the body 431 and extends along a linear trajectory. The first weak portion 432 is provided on an outer surface of the body 431, and the second weak portion 433 is provided on an inner surface of the body 431. A first projection 4321 of the second weak portion 433 on a plane perpendicular to the first direction z, which is the thickness direction of the relief portion 4311, and a second projection 4331 of the second weak portion 433 on the plane do not intersect. The pressure relief portion 4311 is configured to open and turn toward the side where the second weak portion 433 is located with the first weak portion 432 as a boundary when the pressure or temperature inside the battery cell reaches a threshold value.

The scheme of the embodiment can improve the anti-damage capability of the pressure relief mechanism, promote the effective pressure relief of the battery monomer, and prolong the service life of the battery monomer, thereby improving the safety of the battery.

According to some embodiments of the present application, there is provided a battery cell including the housing 40 of the above embodiments.

The scheme of the embodiment can improve the anti-damage capability of the pressure relief mechanism, promote the effective pressure relief of the battery monomer, and prolong the service life of the battery monomer, thereby improving the safety of the battery.

According to some embodiments of the present application, there is provided a battery including the battery cell of the above embodiments.

The scheme of the embodiment can improve the anti-damage capability of the pressure relief mechanism, promote the effective pressure relief of the battery monomer, and prolong the service life of the battery monomer, thereby improving the safety of the battery.

According to some embodiments of the present application, there is provided an electric device including the battery in the above embodiments, wherein the battery is used for providing electric energy.

The scheme of the embodiment can improve the anti-damage capability of the pressure relief mechanism, promote the effective pressure relief of the battery monomer, and prolong the service life of the battery monomer, thereby improving the safety of the battery.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present disclosure, and the present disclosure should be construed as being covered by the claims and the specification. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims (23)

1. A single shell for a battery, includes pressure relief mechanism, its characterized in that, pressure relief mechanism includes:

a body;

the first weak part is arranged on the body and provided with two first free ends, and a connecting line of the two first free ends is not completely overlapped with the first weak part and defines a pressure relief part together; and

a second weak portion provided to the body, a first projection of the first weak portion on a plane perpendicular to a first direction that is a thickness direction of the pressure relief portion and a second projection of the second weak portion on the plane do not intersect,

wherein the pressure relief portion is configured to open and turn over toward a side where the second weak portion is located, with the first weak portion as a boundary, when a pressure or a temperature inside the battery cell reaches a threshold value.

2. The enclosure of claim 1, wherein the body has a first relief groove and a second relief groove formed therein, the first weakened portion being a bottom wall of the first relief groove, the second weakened portion being a bottom wall of the second relief groove.

3. The housing of claim 2, wherein the first relief groove is located on a first surface of the body and the second relief groove is located on a second surface of the body opposite the first surface.

4. The enclosure of claim 3, wherein the first surface is an outer surface of the body and the second surface is an inner surface of the body.

5. The enclosure of claim 2, wherein the first relief groove has a depth greater than a depth of the second relief groove, and the first frangible portion has a thickness less than a thickness of the second frangible portion.

6. The housing according to any one of claims 2 to 5, wherein the first pressure relief groove includes a plurality of first groove portions, the plurality of first groove portions being arranged in order in a depth direction of the first pressure relief groove, and a width of the plurality of first groove portions gradually decreases in the depth direction of the first pressure relief groove.

7. The housing according to any one of claims 2 to 5, wherein the second pressure relief groove includes a plurality of second groove portions that are arranged in order in a depth direction of the second pressure relief groove, and widths of the plurality of second groove portions gradually decrease in the depth direction of the second pressure relief groove.

8. A housing according to any one of claims 1 to 5, characterized in that a line connecting the two first free ends has a third projection on said plane, the extension direction of said second projection coinciding with the extension direction of said third projection.

9. A housing according to claim 8, characterized in that the second projection at least partially overlaps the third projection in a direction perpendicular to the extension direction of the second projection.

10. The enclosure of claim 8, wherein the second projection is located on a side of the third projection adjacent to the first projection and spaced apart from the third projection.

11. A casing according to claim 8, wherein the second projection is located on a side of the third projection facing away from the first projection and spaced from the third projection.

12. The enclosure of claim 8, wherein the perpendicular bisector of the third projection coincides with the perpendicular bisector of the second projection.

13. The housing of claim 8, wherein the first projection is symmetrical with respect to a mid-normal of the third projection.

14. A housing according to claim 8, characterized in that the second projection has two second free ends, and wherein the minimum gap between one second free end and the first projection is not more than one third of the length of the third projection, and/or

The minimum gap between the other second free end and the first projection is no more than one third of the length of the third projection.

15. A casing according to claim 14, wherein a minimum gap between one of the second free ends and the first projection is less than 10mm, and/or

The minimum gap between the other of said second free ends and said first projection is less than 10mm.

16. A casing according to any one of claims 1 to 5, wherein the first projection is arcuate, dog-legged or a combination of arcuate and dog-legged.

17. The shell according to any one of claims 1 to 5, wherein the shell comprises a shell body with an opening and an end cover covering the opening, a containing cavity for containing the battery cell is formed between the shell body and the end cover, and the pressure relief mechanism is arranged on at least one side wall of the shell body and/or the end cover.

18. The housing of any one of claims 1-5, wherein a groove is formed on the housing, and the body of the pressure relief mechanism is a bottom of the groove.

19. The enclosure of claim 18, wherein the side walls of the recess include opposing first and second side walls, a direction of extension of a projection of the first side wall onto the plane coincides with a direction of extension of the first projection, and a direction of extension of a projection of the second side wall onto the plane coincides with a direction of extension of the second projection.

20. A casing according to any one of claims 1 to 5, wherein the thickness of the body is less than the thickness of the part of the casing other than the pressure relief mechanism.

21. A battery cell, comprising:

the enclosure of any one of claims 1-20.

22. A battery comprising the cell of claim 21.

23. An electrical device comprising the battery of claim 22, wherein the battery is configured to provide electrical energy.

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